Obstetrics Flashcards
What is gestational age? What do G and P refer to? What are the trimesters and when do foetal movements start
Gestational age is calculated from last menstrual period. EDD is 40 weeks gestation.
Gravida - number of pregnancies
Para/parity - number of deliveries after 24 weeks
First trimester - up to 12 weeks
Second trimester - 13-26 weeks
Third trimester - >27 weeks
Foetal movements start at 20 weeks
Hormonal changes in normal pregnancy
(Anterior pituitary hormones, TSH, HCG, Progesterone, Oestrogen)
Also give role of progesterone, and how does HCG rise
Anterior pituitary produces more prolactin, ACTH and melanocyte stimulating hormone.
Prolactin suppresses FSH and LH
ACTH increases cortisol and aldosterone (improvement in autoimmune conditions, increased susceptibility to diabetes)
MSH causes pigmentation of skin
TSH stays normal but T3/T4 rise
HCG rises, doubling every 48 hours until they plateau 8-12 weeks then gradually fall
Progesterone rises throughout pregnancy, maintaining pregnancy, preventing contractions and suppressing immunity to foetus. Corpus luteum produces for first 10 weeks, then placenta.
Oestrogen rises throughout, produced by placenta
What normally happens to blood pressure in pregnancy? What is defined as hypertension in pregnancy?
It falls during first trimester, and stays low until 20-24 weeks, then returns to normal.
HTN in pregnancy at >140 or >90 diastolic. OR increase of >30 or >15 diastolic
How is high risk of preeclampsia treated
75mg aspirin from 12 weeks gestation until birth
What should be done in a woman with HTN that becomes pregnant
If >140/90 before 20 weeks gestation, this is pre-existing HTN.
If taking ACEi or ARB, this should be stopped, and switched to alternative. Oral labetalol first line. (Nifedipine or hydralazine if asthmatic)
What is the difference between pre-eclampsia and pregnancy induced HTN
HTN (>140/90) in 2nd half (>20 weeks)
If symptomatic with proteinuria (>0.3g/24 hours) and/or oedema. this is pre-eclampsia.
if asymptomatic this is PIH (AKA Gestational hypertension). This resolves after birth, but increases risk of pre-eclampsia or HTN later in life.
Define pre-eclampsia
New >140/90 after 20 weeks gestation AND
- Proteinuria OR
- Other symptoms (oedema, renal insufficiency (Creatinine >90), etc)
Features of severe pre-eclampsia and how is it managed
- > 160/110
- Headaches and visual disturbance
- Papilloedema
- RUQ/Epigastric pain
- Hyperreflexia
- Reduced platelet count, abnormal liver enzymes or HELLP Syndrome
Magnesium sulfate for prevention of eclampsia
What can Pre-eclampsia cause, ti foetus, and to mother
- Eclampsia
- Foetal complications (intrauterine growth retardation, prematurity)
- Liver disease
- Haemorrhage (placental abruption, intra cerebral)
- Cardiac failure
- Neurological symptoms (stroke, altered mental status, blindness)
What are some high risk factors for pre-eclampsia
- HTN, in previous pregnancy or chronic
- CKD
- SLE or Antiphospholipid syndrome
- Diabetes
What are moderate risk factors for pre-eclampsia (>2 for prevention)
- First pregnancy
- > 40y
- > 10y since last pregnancy
- Obesity
- Family history
- Multiple pregnancy
If pre-eclampsia is found at 160/100 or higher, how should it be managed
Emergency secondary care assessment, admission and monitoring if >160/110
What is eclampsia
Development of seizures in association with pre-eclampsia
How is eclampsia managed
Magnesium sulphate.
- For prevention in severe pre-eclampsia and to treat seizures.
- IV bolus of 4g over 5-10 mins then 1g/hour infusion
- Monitor urine output, resp rate and O2 sats
- Until 24 hrs post last seizure or delivery
What should be monitored in patients with pre-eclampsia/Gestational HTN. What factor decreases in pre eclampsia
Urine dipstick, liver enzymes, FBC, renal profile weekly
Monitor foetal growth on scans
Platelet Growth Factor (PlGF) once between 20-35 weeks to rule out pre-eclampsia (PlGF is low in pre-eclampsia)
What is HELLP syndrome, how does it present, and how is it treated
Combination of features as a complication of pre-eclampsia
- Haemolysis
- Elevated Liver enzymes
- Low Platelets
Nausea/vomiting, RUQ pain and lethargy
Treated with delivery of child
What is gestational diabetes and what does it cause
Diabetes complicates 1/20 pregnancies, majority of which is gestational diabetes - insulin resistance during pregnancy which resolves after birth.
Most commonly it causes larges for dates fetus and macrosomia, implications for delivery including shoulder dystocia.
Also puts woman at further risk of T2DM.
Risk factors for Gestational Diabetes
BMI>30
Previous gestational diabetes
Previous macrosomic baby >4.5kg
First degree relative with diabetes
Family origin (South Asia, black Caribbean and Middle East)
How is gestational diabetes screened for, and when is this offered
OGTT (fasting glucose, followed by 75g glucose drink. Blood sugar measured again after 2 hrs. Normal, fasting: <5.6mmol/L, 2hrs: <7.8 mmol/L (!5678!))
In those with previous this is offered at first antenatal appt, and repeated 24-28 weeks if normal.
If risk factors, 24-28 week test.
If features (large for dates fetus, polyhydroamnios, glucose on urine dip, then do test)
How should gestational diabetes be managed
- Counselling, diet, exercise, and show how to take blood glucose.
- If fasting <7, trial non medical.
- If targets not met, add metformin
- If still not met add insulin
If >7 add insulin
How should pre existing diabetes be managed in pregnancy? What non diabetic drug needs to be given?
Weight loss if BMI>27
Stop oral drugs except metformin, and start insulin
Folic acid 5mg/day until 12 weeks
Glucose self monitoring targets in pregnancy
Fasting 5.3
1 hr after meals 7.8
2 hr after meals 6.4
Define miscarriage
The spontaneous loss of pregnancy before 24 weeks gestation.
Most common in first trimester and usually present with vaginal bleeding +- lower abdominal pain.
What is the most common cause of miscarriage, and how many known pregnancies are affected by miscarriage
Chromosomal abnormalities in fetus are most common.
Affects 1 in 8 known pregnancies
Risk factors for miscarriage
Maternal age >35
History of miscarriage
Previous large cervical cone biopsy
Smoking, alcohol, obesity
Uncontrolled diabetes or thyroid disorders
Define these:
Missed miscarriage
Threatened miscarriage
Inevitable miscarriage
Incomplete miscarriage
Complete miscarriage
Anembryonic pregnancy
Missed - Fetus no longer alive, no symptoms of expulsion, before 20 weeks. Closed cervical os
Threatened - Painless vaginal bleeding but closed cervix and fetus alive (usually 6-9 weeks, can be anytime before 24wk)
Inevitable - Heavy painful bleeding with clots and open cervix
Incomplete - Conception products still in uterus. Pain and vaginal bleeding with open cervical os
Complete - Full miscarriage, no products of conception in uterus
Anembryonic - Gestational sac but no embryo
What is vaginal bleeding and symptoms caused by in miscarriage
- Haemorrhage in decidua basalis leading to necrosis and inflammation
- Ovum unable to continue developing causing uterine contractions and cervical dilation, causing loss of fetus and pregnancy tissue
What investigations are used to diagnose a miscarriage
Transvaginal ultrasound scan determines the viability and the location of the pregnancy.
If unable to determine, repeat in 7 days.
Serum bHCG can be done, decreases following miscarriage as produced by placenta. If ectopic, laparoscopy can be done.
Whats looked for in a transvaginal ultrasound in early pregnancy
Findings appear sequentially, and earlier features less relevant when later develop.
- Mean gestational sac diameter
- Fetal pole and crown-rump length
- Fetal heartbeat
Fetal pole is expected once mean gestational sac diameter is >25mm. If GSD is >=25mm and no fetal pole, repeat in 1 week before confirming anembryonic pregnancy
If crown-rump<7mm and no heart beat, repeat in 7 days. If >7mm without heartbeat, repeat scan in 1 week and confirm non-viable pregnancy.
With fetal heartbeat, pregnancy viable. Expected once crown-rump length is 7mm.
What are the 3 ways miscarriage can be managed
Expectant: If no major risk factors (bleeding/infection etc), should be given 1-2 weeks to pass.
Medically: Misoprostol (prostaglandin analogue) causes strong myometrial contractions, expelling the contents of conception. Can be given vaginally or orally.
Surgical: vacuum aspiration (local anaesthetic/outpatient), surgical under general anaethetic
How is a missed miscarriage treated
Mifepristone (progesterone receptor antagonist - weakens attachment to endometrial wall + cervical softening and dilation + induction of contractions)
48 hours later give misoprostol unless already passed.
How is incomplete miscarriage managed
Single dose of misoprostol (vaginal, oral or sublingual).
May need vacuum suction too, as retained conception contents are an infection risk.
Differentials for miscarriage
Ectopic pregnancy - Pain unilateral, more severe and before bleeding. Darker blood and less heavy.
Molar pregnancy - Heavy and prolonged bleeding with clots and brown watery discharge. Uterus is large for date and exaggerated morning sickness
Ovarian torsion - Palpable mass with pelvic pain and may not bleed.
Fibroid degeneration - May have fever, more systemic, swelling
Complications of miscarriage
- Incomplete miscarriage +- infection
- Haemorrhagic shock due to blood loss
- Depression/anxiety
- Haemolytic disease of the newborn - Give anti-D immunoglobulin to rhesus-negative women who have had surgical intervention for miscarriage.
- Increased risk of future miscarriage
What is post partum haemorrhage and what volumes of blood is it characterised by
Blood loss of >500ml after vaginal delivery, or >1000ml after C section. Can be primary or secondary
Causes of primary post partum haemorrhage
Within 24 hours.
4 Ts
- Tone (uterine atony - most common)
- Trauma (e.g. perineal tear)
- Tissue (retained placenta)
- Thrombin (Clotting/bleeding disorders)
Risk factors for Primary PPH
Previous PPH
Prolonged labour
Pre-eclampsia
Polyhydramnios
Emergency C Section
Macrosomia
Increased maternal age
Preventative measures for PPH
Treating antenatal anaemia
Giving birth with empty bladder
Active management of third stage (IM oxytocin)
IV tranexamic acid during C section in third stage in high risk patients.
Management of PPH (general, not necessarily addressing bleeding)
Medical emergency
Resuscitation with ABCDE
Lie flat, keep her warm.
Insert 2 14 gauge cannulae
Take bloods with group and save
Commence warmed crystalloid
Oxygen and blood transfusions.
Activate major haemorrhage protocol!
Management to stop bleeding in PPH
(2 meds have contraindications, what are they?)
Mechanical: Palpate and rub uterine fundus to stimulate contractions. Catheterisation (bladder distension prevents uterine contraction)
Medical:
- IV Oxytocin, slow injection then infusion
- Ergometrine IV or IM (unless HTN) - Stimulates smooth muscle contraction
- Tranexamic acid (antifibrinolytic - prevents bleeding)
- Carboprost IM (unless asthmatic) - Prostaglandin analogue, stimulates uterine contraction
- Misoprostol
Surgical:
- Intrauterine balloon tamponade (Bakri)
- B-Lynch suture (suture around uterus to compress)
- Uterine artery litigation
What is secondary PPH, how is it investigated and treated
Bleeding from 24 hours to 12 weeks post partum.
Usually due to Retained Products of Conception (RPOC) or infection e.g. endometritis.
USS and/or endocervical or high vaginal swabs
Treated with surgery or Abx
When does labour normally occur and what are its stages
between 37 and 42 weeks
1 - Onset of labour (true contractions) until 10cm cervical dilatation
2 - 10cm cervical dilatation to delivery of the baby
3 - From delivery of baby to delivery of placenta
What happens during the first stage of labour
Cervical dilatation and effacement (thinning). The “show” (mucus plug that normally prevents bacteria from entering uterus) is passed, falling out and creating space for baby to pass through.
What are the 3 phases of the first stage of labour
Latent - 0 to 3cm dilatation. ~0.5cm/hour with irregular contractions
Active - 3 to 7cm dilatation. ~1cm/hour with regular contractions
Transition phase - 7 to 10cm dilatation. ~1cm per hour with regular strong contractions.
If a woman feels irregular, non labour contractions during pregnancy, what are these called and when do they normally happen.
Braxton-Hicks contractions.
Irregular uterus contractions usually during second or third trimester. Not true contractions, no indication of labour. Non progressive and irregular.
Staying hydrated and relaxing can help.
Give 4 signs of labour
Show (cervical mucus plug)
Rupture of membranes
Regular, painful contractions
Dilating cervix on examination
What prostaglandin can be used to induce labour
Prostaglandin E2 (dinoprostone)
What is the second stage of labour and how long should it last
From 10cm until delivery of baby
Passive 2nd stage - Delivery without pushing (normal)
Active - Active process of maternal pushing
It is less painful than stage 1 and should last 1 hour. If longer, consider Ventouse, forceps or C section.
What factors most dictate success of second stage
3 Ps
Power - Strength of uterine contractions
Passage - Size and shape of passageway and pelvis
Passenger (4 descriptive qualities of fetus)
- Size (especially head
- Attitude: Posture (how back is rounded, how head and limbs are flexed)
- Lie: Position of child in relation to mother’s body
- Presentation: Part of fetus closest to cervix
Explain the 4 descriptive qualities of the fetus in second stage, giving best and worst presentations.
And how should head position be
Size: Normal or small head. Macrosomia can cause difficulty passing through birth canal, causing complications like shoulder dystocia.
Attitude (posture): Well flexed head, rounded back and tucked in limbs best for delivery.
Lie (childs long axis compared to mother’s): Longitudinal best - fetus head or buttocks down, lining up wiht mother. Transverse not compatible with vaginal delivery needs C section.
Presentation (part of fetus closest to cervix): Cephalic (head first) best. Breech (legs first) or shoulder presentation may need c section.
Head position being occiptoanterior is best.
How should contractions occur in normal labour, how often should they occur and how long should they last
Regular, strong contractions - every 2-3 mins and lasting 60-90 seconds.
Weak, infrequent or uncoordinated contractions bad, may need oxytocin or c section
How should pelvis be ideally shaped in labour
Gynaecoid - round and spacious
Worst: Android - Narrow and heart shaped
What is the 3rd stage of labour, what are the benefits of a an active 3rd stage
Completed baby birth to placental delivery
Physiological - Maternal effort without medication or cord traction
Active management - IM Oxytocin and careful traction to umbilical cord help deliver placenta.
Active shortens 3rd stage and reduces risk of bleeding. Haemorrhage or >60min delay should prompt active management.
What are the 7 cardinal movements of labour
Engagement - Babys head enters pelvis
Descent - Downward movement through birth canal
Flexion - Babys head flexes, allowing smallest head diameter to present
Internal rotation - Babys head rotates to align with pelvis
Extension - As head passses under pubic bnoe, it extends up
External rotation (Restitution) - Baby’s head rotates back to align with shoulders
Expulsion - Shoulders and body delivered
How does the head of the baby enter and exit the pelvis
Enters occipito-lateral
Exits occipito-anterior
DEFINE
Prelabour rupture of membranes
Preterm prelabour rupture of membranes
Prolonged rupture of membranes
Prelabour - Amniotic sac ruptures before onset of labour
Preterm prelabour - Prior to labour and before 37 weeks
Prolonged - Rupture more than 18 hours before delivery
Define prematurity
Birth <37 weeks gestation. More premature = worse outcomes.
Non viable before 23 weeks.
Under 28 weeks: Extreme preterm
28-32: Very preterm
32-37: moderate preterm
What prophylaxis can be given for preterm labour? At what age of gestation is this offered and what indicates offering it
Vaginal progesterone. Offered to all women with cervical length of <25cm between 16 and 24 weeks gestation (short cervix)
Cervical cerclage. - Stitching cervix to keep it closed. Offered between 16-24 weeks with <25cm cervical length if previous premature birth or cervical trauma.
If there is cervical dilatation between 16 and 28 weeks, without rupture of membranes, what can be done?
“Rescue” Cervical cerclage (stitching cervix to keep it closed)
How can preterm prelabour rupture of the membranes be diagnosed?
If negative, what fluid tests can be done?
Sterile speculum examination showing pooling of amniotic fluid in the posterior vaginal vault.
If negative, test fluid for placental alpha microglobulin-1 protein (PAMG-1) or insulin-like growth factor binding protein 1
What is a complication of prelabour preterm rupture of membranes and how should it be managed
Prophylactic erythromycin 250mg 4xdaily for 10 days - prevent chorioamnionitis.
Antenatal corticosteroids to reduce risk of respiratory distress syndrome
How does preterm labour with intact membranes present
Regular painful contractions and cervical dilation without rupture of amniotic sac
How is preterm labour with intact membranes diagnosed?
What is an alternative test?
Less than 30 weeks, clinical diagnosis with speculum examination to assess cervical dilatation
> 30 weeks, Transvaginal ultrasound to assess cervical length. If <15mm, preterm labour management. If >15mm, unlikely to be preterm labour.
Fetal fibronectin is an alternative test: found in vagina during labour
Management of preterm labour
Tocolysis with nifedipine - stop uterine contractions between 24 and 34 weeks. Short term measure (<48 hours). Atosiban (oxytocin receptor blocker) is an alternative
Maternal corticosteroids (IM Betamethasone, 2 doses 24 hours apart) - reduce neonatal morbidity and mortality
Magnesium Sulfate IV to mother - helps protect fetal brain during premature delivery, reducing risk and severity of cerebral palsy.
What are signs of magnesium sulfate toxicity? How is it treated
Reduced resp rate
Reduced blood pressure
Absent reflexes
Treated with Calcium gluconate
What is ectopic pregnancy
Fertilised ovum implants outside uterine cavity, most commonly fallopian tubes. Other sites include ovary, cervix, abdominal cavity.
Risk factors for ectopic pregnancy
- Fallopian tube abnormalities or damage (PID, surgery)
- Previous ectopic
- IUD and POP use
- Endometriosis
- Smoking
- Fertility treatments
Typical presentation of ectopic pregnancy
Usually presents with 6-8 weeks of amenorrhoea with lower abdo pain and later, vaginal bleeding.
- Lower abdo pain (caused by tubal spasms) usually constant and unilateral.
- Recent amenorrhoea (6-8 weeks since last period) followed by vaginal bleeding (darker brown and lighter than normal period)
- Peritoneal bleeding causes shoulder tip pain and pain on urination/defecation
Examination findings of ectopic pregnancy
- Abdominal tenderness
- Cervical excitation (cervical motion tenderness)
- Adnexal mass (do not examine, risk of rupturing pregnancy)
Investigations of ectopic pregnancy
bHCG >1500
GOLD: Transvaginal ultrasound: gestational sac containing yolk sac or fetal pole.
Findings on TVUSS:
- blob/bagel/tubal ring sign (empty gestational sac)
- Empty uterus
- Fluid in the uterus (psuedogestational sac)
How does bhCG increase in:
- Intrauterine pregnancy
- Ectopic
- Miscarriage
Over 48 hours
Intrauterine: Increase of more than 63%
Ectopic: Increase of less than 63%
Miscarriage: Fall of >50%
How can ectopic pregnancy be managed
If pelvic pain/tenderness + positive pregnancy test, refer to early pregnancy assessment unit (EPAU).
Expectant - await natural termination
Medical - Methotrexate
Surgical - Salpingectomy
Criteria for expectant and medical management of ectopic pregnancy
Size <35mm
Unruptured
Asymptomatic
No fetal heartbeat
hCG <1000
48 hour monitoring
If: hCG >1500, but less than 5000, and if intrauterine pregnancy absence confirmed, methotrexate can be used.
When is surgical intervention indicated in ectopic pregnancy
Size >35mm
Can be ruptured
If significant pain
Visible fetal heartbeat
hCG >5000
Can be done if another intrauterine pregnancy
Done via laparoscopic salpingectomy
Why is treatment with methotrexate incompatible with another pregnancy. Give possible side effects of use
Methotrexate is given IM, and is teratogenic. Halts pregnancy and causes spontaneous termination.
Should not get pregnant for 3 months following treatment.
Common side effects:
- Vaginal bleeding
- Nausea/vomiting
- Abdo pain
- Stomatitis (inflammation in mouth)
What is placenta accreta spectrum
When the placenta implants too deep through endometrium to the myometrium or perimetrium (placenta percreta) due to a defective decidua basalis. As it does not properly separate, this can cause postpartum haemorrhage.
If chorionic villi invade into myometrium, placenta increta. If they simply attach to the myometrium instead of remaining in the decidua basalis, placenta accreta. (INvade = INcreta)
Accreta - Attaches to myometrium
Increta - Chorionic villi invade into myometrium (uterine muscles)
Percreta - Through myometrium into perimetrium or nearby organs (e.g. bladder)
What can cause placenta accreta and what are its risk factors
Previous uterine surgery e.g. C section, curettage procedures.
- Previous placenta accreta
- Previous endometrial curettage procedures
- Previous c section
- Multigravida
- Increased maternal age
- Low lying placenta or placenta praevia
How does placenta accreta normally present
Usually no symptoms during pregnancy, but can be bleeding during third trimester. (antepartum haemorrhage)
May be diagnosed on routine antenatal ultrasounds or at birth, with difficulty delivering placenta.
What is the big worry with placenta accreta
Postpartum haemorrhage!
How is placenta accreta managed
Specialist MDT. Planned delivery between 35-37 weeks. Antenatal steroids given to mature fetal lungs and C section conducted.
Options during C section:
- Hysterectomy (recommended)
- Uterus preserving surgery
- Expectant management (carries significant bleeding and infection risk)
Main 3 causes of major and minor (spotting) antepartum bleeding
Major
- Placenta praevia
- Placental abruption
- Vasa praevia
Minor
- Cervical ectropion
- Infection
- Vaginal abrasion from sex or procedures
What is placenta praevia
When the placenta lies wholly or partly over the cervical os. Major cause of mortality and morbidity, and is indication for C section.
It is a worse version of a low lying placenta, as low lying placentas usually resolve upwards.
How is placenta praevia normally diagnosed
20 week anomaly scan (transvaginal USS) used to assess placenta position.
Usually asymptomatic but is a cause of 3rd trimester bleeding (antepartum haemorrhage), which can be major
NO Digital vaginal exam, as this could provoke major haemorrhage.
Grading of placenta praevia
I - Reaches lower segment but not internal os
II - Reaches internal os but doesnt cover it
III - Covers internal os before dilation but not when dilated
IV (major) - Placenta completely covers internal os.
Risk factors for placenta praveia
Multiparity
Uterine scarring due to previous C section, uterine rupture, or endometriosis
Previous placenta praevia
Advanced maternal age
Management of placenta praevia
- Repeat USS at 32 and 36 weeks.
- Corticosteroids at 34 and 35+6 weeks to mature fetal lungs.
- Planned C section between 36 and 37 weeks.
Complications of placenta praevia
- Haemorrhage, either before. during or after delivery.
- Preterm or low weight birth
- Stillbirth
- Emergency C section or hysterectomy may be indicated
What is placental abruption
When compromise of the vascular structures supporting the placenta separate from the wall of the uterus causing bleeding into the new space under attachment site. Causes a solid woody feeling abdomen
Risk factors for placental abruption
Preeclampsia
Cocaine use
Smoking
Maternal trauma
Multiparity
Increasing maternal age
A for Abruption previously;
B for Blood pressure (i.e. hypertension or pre-eclampsia);
R for Ruptured membranes, either premature or prolonged;
U for Uterine injury (i.e. trauma to the abdomen);
P for Polyhydramnios;
T for Twins or multiple gestation;
I for Infection in the uterus, especially chorioamnionitis;
O for Older age (i.e. aged over 35 years old);
N for Narcotic use (i.e. cocaine and amphetamines, as well as smoking)
Presentation of placental abruption
- Sudden, severe, continuous abdominal pain
- Tender, tense uterus
- Vaginal bleeding (antenatal haemorrhage)
- Characteristic “woody” abdomen on palpation suggests large bleed
- Shock (tachycardia and hypotension) if severe bleeding
- Absent fetal heart suggests fetal death
How can an abruption remain concealed
If cervical os remains closed, or any bleeding occurs away from cervical os, containing blood.
Management of placental abruption
Fetus alive <36 weeks
- If distressed: Immediate C section
- If not, observation and steroids
Fetus alive >36 weeks
- If distressed, immediate C section
- If not, normal delivery
If fetus is dead, induce delivery.
Complications of placental abruption
Maternal
- Hypovolaemic Shock
- PPH
- DIC
- Renal failure
Fetal
- Intrauterine growth restriction (IUGR)
- Hypoxia
- Death
How is bleeding categorised in Placental abruption
Spotting (may not need intervention)
Minor - <50ml
Major 50-1000ml
Massive >1000ml
What is vasa praevia
Rare condition where fetal blood vessels in chorioamniotic membranes cross the interal cervical os. Fetal membranes surround amniotic cavity and developing fetus.
Fetal vessels consist of 2 umbilical arteries and an umbilical vein.
Pathophysiology of vasa praevia (including types)
Fetal vessels (2 umbilical arteries and umbilical vein) usually protected by umbilical cord (Wharton’s jelly) or by the placenta. 2 cases where they can become exposed:
- Velamentous umbilical cord - cord inserts into chorioamniotic membranes, and vessels travel unprotected through membranes before joining placenta. (TYPE 1)
- Accessory lobe of placenta - AKA a succenturiate lobe. When fetal vessels travel through chorioamniotic membranes between lobes. (TYPE 2)
In vasa praevia, the unprotected vessels travel through membranes and pass across the cervical os, becoming exposed and prone to bleeding. Especially during membrane rupture during labour, which can lead to fetal blood loss and death.
Diagnosis of vasa praevia
May be diagnosed via USS in pregnancy, enabling planned C section.
May present with antepartum haemorrhage.
May be detected during labour, when pulsating vessels seen during dilation.
May be detected when dark red bleeding and fetal distress occur during labour - high mortality.
Management of vasa praevia
Corticosteroids at 34 weeks
Elective C section 34-36 weeks
What is cord prolapse and whats its most significant risk factor
Where the umbilical cord descends below presenting part of fetus into vagina after rupture of fetal membranes during delivery. If cord is compressed, can cause fetal hypoxia.
Most significant risk factor is an abnormal lie (Unstable, transverse or oblique). Being in an abnormal lie provides space for cord prolapse below presenting part.
Diagnosis of cord prolapse, and what is a big cause of them
50% occur at artificial rupture of the membranes. Diagnosis made when fetal heart rate becomes abnormal and cord is palpable or visible vaginally.
Management of cord prolapsee
Obstetric emergency
Push presenting part of baby back and keep cord warm and moist to prevent vasospasm.
Have mother go on all fours (knee-chest position) or in a left lateral lie to draw fetus away from pelvis and reduce compression.
Tocolytic medication (terbutaline) can minimise contractions while waiting for emergency C section
What is rhesus disease?
Rhesus-D is an antigen found on blood cells. A rhesus positive mother won’t need treatment, but if rhesus negative, and her child is rhesus positive, this could be a problem;
If there is an event causing leakage, or when fetal and maternal blood is mixed during labour, the mother’s immune system can become sensitised to the rhesus D antigen, forming anti-D IgG antibodies.
In a second rhesus D positive pregnancy, these can cross the placenta and cause haemolysis of the fetal red blood cells. This is referred to as haemolytic disease of the newborn.
How is rhesus disease prevented
Test for D antibodies in all Rh negative mothers at booking.
Giving anti-D to non-sensitised mothers at 28 and 34 weeks, and at birth, prevents sensitisation, as once sensitised this is irreversible.
Anti D should be given ASAP (<72hrs) if:
- Delivery of Rh +ve infant in Rh negative woman
- Any termination of pregnancy
- Miscarriage if >12 weeks gestation
- Ectopic pregnancy (unless managed with methotrexate)
- any situation where sensitisation may occur (amniocentesis procedures, antepartum haemorrhage, abdominal trauma)
What test is performed after 20 weeks in rhesus negative women who have had a sensitising event
Kleinhauer test
- after any sensitising event after 20 weeks, add acid to sample of mother’s blood. Fetal blood is naturally resistant to acid so they are protected against acidosis, keeping their haemoglobin, enabling a measurement of how much fetal blood is in the mother’s blood.
What tests should be done on all babies born to a Rh -ve woman
FBC
Blood group
Direct coombs test (Demonstrate antibodies on baby’s RBCs)
What are possible complications to a fetus in rhesus negative pregnancy
- Oedematous (hydrops fetalis)
- Jaundice, anaemia, hepatosplenomegaly
- Heart failure
- Kernicterus (newborn jaundice)
Treated with transfusions and UV phototherapy.
What are some indications for induced labour?
- Prolonged pregnancy (38/39 weeks)
- Premature prelabour rupture of membranes where labour doesnt start
- Maternal medical problems (diabetes >38 weeks, pre-eclampsia, obstetric cholestasis)
- Intrauterine fetal death
What score is used to figure out whether a labour may need to be induced
Bishop score
Looks at:
Cervical position (anterior best (+ 2))
Cervical consistency (soft best +2)
Cervical effacement (80% best +3, 60-70% +2)
Cervical dilation (>5cm best +3, 3-4 +2)
Fetal station (+1 and +2 are best (+3 points), -1 and 0 (+2 points), -3 is worst at (0 points))
<5 indicates labour unlikely without induction
>8 indicates cervix is ripe and high chance of spontaneous labour, or response to induction
Possible methods of labour induction
- Membrane sweep - Finger passes through cervix to rotate against wall of uterus, to separate chorionic membrane from decidua. Adjunct to labour
- Vaginal prostaglandin E2 (dinoprostone)
- Oral prostaglandin E1 (misoprostol)
- Maternal oxytocin infusion
- Amniotomy (breaking of waters)
- Cervical ripening balloon (passed through endocervical canal to dilate cervix)
What are the NICE Guidelines for inducing labour
Bishop <6, Vaginal or oral prostaglandin (E2 dinoprostone or E1 misoprostol respectively)
- Balloon catheter if high hyperstimulation risk or previous caesarean
- Bishop >6, amniotomy and IV oxytocin.
Main complication of labour induction
Uterine hyperstimulation
- Prolonged and frequent uterine contractions (tachysystole)
- Can cause intermittent interruption of bood flow to child causing fetal hypoxemia and acidemia
- Can be treated by stopping prostaglandin or oxytocin, or with tocoloysis
Why should VTE risk assessment be done in a pregnant woman
Pregnancy is a VTE risk
How is VTE risk in pregnancy managed pharmacologically
Using LMWH (Warfarin and DOACs AVOIDED)
- Woman with previous VTE high risk - needs LMWH throughout antenatal period
- Woman with risk of VTE due to hospitalisation, surgery, comorbidities, thrombophilia, consider for treatment
Risk factors for VTE
Based on these, how should VTE Risk be managed?
- Age >35
- BMI>30
- Parity >3 and multiple pregnancy
- Smoker
- Varicose veins
- Preeclampsia
- Immobility
- Family history of unprovoked VTE
- Low risk thrombophilia
- IVF pregnancy
4 or more = immediate treatment until 6 weeks postnatal.
3 or more = LMWH from 28 weeks until 6 weeks postnatal
If DVT made before delivery, continue for 3 months after
What is the current age of gestation abortion can be performed until, and what legal framework dictates this
24 weeks
(originally 28 weeks according to 1967 abortion act, 1990 Human Fertilisation and Embryology Act changed to 24)
What are some cases where age of gestation can be ignored for abortion
- To save woman’s life
- Evidence of fetal abnormality (physical/mental handicap)
- Risk of serious physical/mental injury to woman
What must be done medico-legally in cases of an abortion and what must be given to women having an abortion after 10 weeks
- 2 registered medical practitioners must sign document (1 if emergency)
- Only a registered medical practitioner can perform an abortion (NHS or licensed premisis)
Give anti-D prophylaxis who are rhesus negative
How can abortion be done medically
Mifepristone (anti-progesterone) followed 48 hours later by prostaglandins (e.g. oral misoprostol) to stimulate contractions
- “mimics a miscarriage”
- Takes hours to days to complete, unpredictable
- Pregnancy test 2 weeks later to confirm, measuring hCG
Can be done at home <10 weeks.
How can abortion be done surgically
Vacuum aspiration, electric vacuum aspiration and dilatation and evacuation.
- Cervical priming with misoprostol or mifepristone before procedures
- After evacuation of uterine cavity, an intrauterine contraceptive can be used immediately.
What are some complications of abortion
Vaginal bleeding and cramps intermittently for up to 2 weeks. Also:
- Bleeding
- Pain
- Infection
- Failure
- Damage to cervix, uterus, other structures
When are women screened for anaemia in pregnancy, and what are the normal ranges during pregnancy
Booking clinic and at 28 weeks
Booking: >110g/L
28 weeks: >105g/L
Post partum: >100g/L
What is a physiological cause of a reduced haemoglobin concentration in pregnancy
Plasma volume increases, reducing haemoglobin concentration
What is the most common cause of Low MCV (mean cell voume) anaemia, as well as normal and high
Low - Iron
Normal - Physiological, due to plasma volume increase
High - B12/ferritin
Treatment of iron deficiency anaemia in pregnancy
Iron replacement (ferrous sulphate 200mg 3 times daily)
(supplementary iron if not pregnant)
Management of B12 deficiency in pregnancy
Test for pernicious anaemia (intrinsic factor antibodies)
- IM Hydroxycobalamin injections
- Oral Cyanocobalamin tablets
Management of folate deficiency in pregnancy
All should be taking 400mcg per day folic acid anyway.
Start on folic acid 5mg daily
Define obesity in pregnancy
BMI >30kg/m^2 at first antenatal visit
Maternal risks with obesity in pregnancy
- Miscarriage
- VTE
- Gestational Diabetes
- Pre-eclampsia
- Dysfunctional labour, induced labour
- Postpartum haemorrhage
- Wound infection
- C section
Fetal risks with obesity in pregnancy
- Congenital abnormalities
- Prematurity
- Macrosomia
- Stillbirth
- Increased risk of obesity and metabolic disorders in childhood
- Neonatal death
Management of obesity in pregnancy
- 5mg folic acid, rather than 400 mcg
- Screening for gestational diabetes (OGTT) 24-28 weeks
- BMI >35 = consultant led obstetric unit
- > 40 = antenatal consultation with obstetric anaesthetist
Define these terms in relation to a multiple pregnancy
- Monozygotic
- Dizygotic
- Monoamniotic
- Diamniotic
- Monochorionic
- Dichorionic
- Monozygotic - Identical twins (one zygote)
- Dizygotic - Non-identical twins (2 zygotes)
- Monoamniotic - Single amniotic sac
- Diamniotic - 2 amniotic sacs
- Monochorionic - Single placenta
- Dichorionic - 2 seperate placentas
Dichorionic, Diamniotic twin pregnancies have best outcomes, due to own nutrient supply.
What can be done to diagnose a multiple pregnancy
Transvaginal USS
- Gestational age
- Number of placentas and amniotic sacs
- Risk of Down’s syndrome (as part of combined test)
How do USS signs determine the type of twins
Dichorionic diamniotic have a membrane between twins
Lambda sign or twin peak sign (triangular appearance of space where membrane meets the chorion)
Monochorionic diamniotic have a membrane between twins with a T sign
Monochorionic monoamniotic twins have no membrane separating them.
What are possible complications of a multiple pregnancy
Mother:
- Anaemia
- Polyhydramnios (excess amniotic fluid)
- HTN
- Spontaneous preterm birth
- Postpartum haemorrhage
Fetuses
- Miscarriage/stillbirth
- Fetal growth restriction
- Prematurity
- Twin-Twin transfusion syndrome
- Twin anaemia polycythaemia sequence
- Congenital abnormalities
What is Twin-Twin Transfusion syndrome
Occurs when twins share a placenta.
When there is a connection of blood supplies from 2 fetuses, one fetus (recipient) may receive more blood, while donor fetus is starved.
The recipient can become overloaded, getting heart failure and polyhydramnios.
Donor has growth restriction, anaemia and oligohydramnios.
May need laser treatment to destroy the connection in blood supplies
What is twin anaemia polycythaemia sequence
Similar to twin-twin transfusion syndrome but less acute. One develops anaemia and the other polycythaemia
How must monoamniotic be delivered
Elective C section between 32 and 33+6 weeks
How can diamnotic twins be delivered
Between 37 and 37+6 weeks
Vaginal possible if first baby has cephalic presentation
C Section may be needed for 2nd child
Elective C section if presenting twin is not cephalic presentation
What is shoulder dystocia
When the anterior shoulder of the baby becomes stuck behind the pubic symphysis of the pelvis, after the head has been delivered.
Obstetric emergency
Often caused by macrosomias secondary to gestational diabetes
Key risk factors for Shoulder Dystocia
- Fetal macrosomia (which is often caused by maternal diabetes)
- High maternal BMI
- Diabetes
- Prolonged labour
How does shoulder dystocia present
- Difficulty delivering the face and head, and obstruction in delivering the shoulders.
- Failure of restitution (head remains facing down (occipito-anterior), and does not turn sideways as expected.
- Turtle-neck sign (head delivered but retracts back in)
- Pain to mother
How is shoulder dystocia managed
Senior help (anaesthetist, paediatrician, obs)
- Pressure to anterior shoulder by pressing suprapubic region of maternal abdomen
- McRoberts’ manoeuvre (flexion and abduction of the maternal hips, bringing thighs to her abdomen. This increases anterior-posterior angle, by moving pubic symphysis out the way)
- Episiotomy can enlarge vaginal opening
- Zavanelli manoeuvre involves pushing baby back in to do C section, but can cause maternal morbidity.
Complications of shoulder dystocia
Maternal
- Postpartum haemorrhage
- Perineal tears
Fetal
- Fetal hypoxia (Subsuquent cerebral palsy)
- Brachial plexus injury and Erb’s palsy.
How should Hypothyroid be managed in pregnancy
Untreated hypothyroid can lead to miscarriage, anaemia, small for gestational age child
Levo dose should be increased and titrated using TSH level.
How should hypertension be managed in pregnnacy
Medication changes
ACEi, ARB and Thiazide diuretics can cause congenital abnormalities
Switch to Labetalol, CCB (nifedipine) or alpha blockers (doxazosin)
How should epilepsy be managed in pregnancy
Take folic acid 5mg, prevent neural tube defects
Manage ideally with single drug. (levetiracetam, lamotrigine, carbamazepine best options)
Sodium valproate causes neural tube defects and developmental delay
Phenytoin causes cleft lip and palate
Rheumatoid arthritis management in pregnancy
- Methotrexate (teratogen, and causes miscarriage)
Hydroxycholorquine first line, safe for pregnancy.
Sulfasalazine and corticosteroids area also safe
What is oligohydramnios and what are some of its causes
Reduced amniotic fluid
- Premature rupture of membranes
- Fetal renal abnormalities (agenesis, dysplasia, obstruction)
- Post term gestation
- Fetal growth restriction
- Post term pregnancy
What can oligohydramnios cause
- Potter sequence (Reduced development of fetal lungs and bilateral renal hypoplasia)
- Flattened facial features (wide set eyes, flat nose, receding chin, low set ears - caused by compression)
- Clubbed feet and limb abnormalities
- Wrinkly skin
How is Oligohydramnios diagnosed
Ultrasound during second trimester
- Usually advanced at diagnosis, and often results in stillbirth, or respiratory problems (pulmonary hypoplasia) so severe they’ll cause death.
Affects boys more
How is oligohydramnios managed
If before term, monitoring with serial fetal testing. Therapeutic amniofusion may be used.
Delivery between 36-38 weeks
What is post partum thyroiditis
Thyrotoxicosis or hypothyroidism, or both, within 12 months of delivery, in a women with previously no thyroid disease.
How does post partum thyroiditis usually present
3 stages
- Thyrotoxicosis (3 months)
- Hypothyroid (3-6 months)
- Return to normal within a year
Anti-TPO found in 90% of patients
Management of post partum thyroiditis
- Thyrotoxic phase: Propanolol for symptom control (no thyroid drugs)
- Hypothyroid phase: Thyroxine
How is postpartum depression screened for
Edinburgh Postnatal Depression Scal
- 10 item questionnaire, maximum score 30
- Score >13 indicates depressive illness
- Indicates how mother has felt for last week
Define baby blues vs postpartum depression vs postpartum psychosis in terms of their respective timings and epidemiology
Baby blues - Majority of women, in first week or so post birth
Postpartum depression - 1/10, peak 3 months after birth
Postpartum/puerperal psychosis - 1/1000, starting a few weeks post birth
How does baby blues present and how is it treated
Mild symptoms, that last a few days and resolve entirely within a couple weeks.
- Anxious/Low mood
- Tearful
- Irritable/mood swings
Treated with reassurance and support. No medical treatment
How does postnatal depression present
Similar to depression (classic triad)
- Low mood
- Low energy
- Anhedonia (lack of pleasure in activities)
Symptoms usually start around 1 month and peak around 3 months post birth
Mild - Treated with support, self help and follow up
Moderate - CBT, talking therapy, Antidepressant medication
Severe - Psychiatry
Medications used in postnatal depression
- SSRI (Sertraline, paroxetine)
- SNRI - Venlafaxine, duloxetine
- Tricyclic antidepressant - amitriptyline
- Monoamine oxidase inhibitor - Slegeline
How does puerperal psychosis present and how is it treated
- Delusions
- Hallucinations
- Depression
- Mania
- Confusion
- Severe mood swings
Urgent assessment and admission to mother and baby unit.
(has a 25-50% chance of recurrence)
What can SSRI use during pregnancy cause
Neonatal abstinence syndrome - poor feeding and irritability. Managed supportively
What does varicella zoster virus (VZV)
Chickenpox as a primary infection. Shingles when the dormant virus reactivates in the dorsal root ganglion.
In pregnancy, there is a risk to both mother and fetus (AKA Fetal varicella syndrome)
Presentation of chickenpox
Widespread erythematous raised vesicular blistering lesions, that usually start on the trunk or face and spread outwards over 2-5 days. Lesions eventually scab, and stop being contagious when they do.
How infective is chickenpox
Highly contagious and spread through direct contact with lesions or infected droplets in cough or sneeze. Symptomatic 10 days-3 weeks after exposure.
Complications of Chickenpox
Bacterial superinfection
Dehydration
Conjunctival lesions
Pneumonia
Encephalitis
The virus lays dormant in sensory dorsal root ganglion cells, and later reactivate as Shingles or Ramsay Hunt Syndrome
What can happen if chicken pox exposure occurs in an unvaccinated pregnant woman before 20 weeks? What about between 20-28 weeks
<20 - low risk, unlikely to progress
20-28 - can cause congenital varicella syndrome (skin scarring, microcephaly, learning disabilities, eye defects, limb hypoplasia)
Treated with VZ immunoglobulins and aciclovir
Management of VZV
Usually self limiting
Aciclovir if immunocompromised, over 14 and presenting within 24 hrs, or neonates at risk of complications.
Management of VZV exposure in pregnancy
Exposure
1- check blood for VZV antibodies
2- IVIG varicella zoster immunoglobulins
3- Oral aciclovir main PEP (Post exposure prophylaxis) 7-14 days post exposure
Management of Chicken pox in pregnancy
Oral aciclovir if >20 weeks and presents within 24 hours of onset
What is breech presentation
Legs and bottom are presenting part of the fetus (upside down).
Complete breech - legs are fully flexed at the hips and knees
Incomplete breech - One leg flexed at hip and extended at knee.
Extended breech - AKA Frank breech - both legs flexed at hip and extended at knee
Footling breech - Foot presenting through cervix with leg extended.
Management of breech
Breech before 36 weeks should turn spontaneously. External Cephalic Version can be used from 37 weeks to turn the fetus.
If ECV fails, can be vaginal or caesarean delivery.
If first baby in twins is breech, C Section is required
Define Uterine rupture
Uterine rupture is a complication of labour in which the myometrium (muscle layer of uterus) ruptures.
With an incomplete rupture, or uterine dehiscence, the uterine serosa (perimetrium) remains intact. In a complete rupture, the serosa ruptures, causing the uterine contents to spill into the peritoneal cavity.
Causes significant bleeding and has high mortality and morbidity for mother and child
Risk factors for uterine rupture
- Previuos C section (scar becomes weak point)
- Vaginal birth after C section
- Previous uterine surgery
- Increased BMI and age
- Induction of labour and oxytocin use
- High parity
Presentation of Uterine rupture
Cessation of uterine contractions
Vaginal bleeding and abdominal pain
Shock (Hypotension, tachycardia, collapse)
How is uterine rupture managed
Emergency C section, stop bleeding and repair or remove uterus (hysterectomy)
What is Asherman’s syndrome
Formation of adhesions within the uterus. following damage to it.
Usually occurs after a dilatation and curettage procedure, e.g. when treating retained products of conception. Can also occur after uterine surgery or pelvic infection.
These adhesions bind uterine walls together, causing a physical obstruction and abnormalities in menstruation, infertility, and recurrent miscarriages
Presentation of Asherman’s syndrome
Significantly lighter, but more painful periods
Secondary amenorrhoea (absent periods)
How are intrauterine adhesions diagnosed
- Hysteroscopy is gold standard, can involve dissection and treatment of adhesions
- Hysterosalpingography - contrast injected into uterus
- MRI
What measurements are used on ultrasound to assess fetal size
- Estimated Fetal Weight
- Fetal abdominal circumference
When is a fetus determined to be small for gestational age? What weight defines low birth weight?
<10th centile
<3rd centile = severe SGA
<2500g = low birth weight
What information is used to plot a growth chart
Mother’s
- Ethnic Group
- Weight
- Height
- Parity
What are causes of SGA
- Constitutionally small (normal for family to be small, growing appropriately on growth chart)
- Fetal Growth Restriction (pathology causing nutrient or oxygen delivery reduction)
What are some mother mediated causes of FGR
- Pre eclampsia
- Maternal smoking and alcohol
- Anaemia
- Infection
- Malnutrition
- Maternal health problems
What are some signs of FGR
- Reduced amniotic fluid volume
- Abnormal doppler studies
- Reduced fetal movements
- Abnormal CTGs
Complications of FGR
- Fetal death/stillbirth
- Birth asphyxia
- Neonatal hypoglycaemia and hypothermia
Increased risk of:
- CVD, particularly HTN
- T2D
- Obesity
- Mood/behavioural problems
What test is used to screen for Down’s syndrome
Combined test -
-Thickened nuchal translucency,
- HCG increased
- PAPP-A (Pregnancy-Associated Plasma Protein A) reduced
Performed between 11-14 weeks. Trisomy 18 (Edwards) and 13 (Pataus) have similar results but lower hCG.
What is the quadruple test
Offered later (15-20 weeks)
Alpha fetoprotein, Unconjugated oestriol, hCG, Inhibin A
Downs:
- AFP ↓
- Unconjugated Oestriol ↓
- hCG ↑
- Inhibin A ↑
Edwards:
- Everything ↓
Neural Tube Defects:
- AFP ↑
How can combined and quadruple test results be assessed and what should be done next
Lower or higher chance
Lower: <1 in 150
Higher: >1 in 150
If higher: offer second screening test (NIPT) or diagnostic test e.g. amniocentesis. NIPT (Non invasive prenatal screening test) is more specific and sensitive.
What is Stillbirth
The death of a fetus after 24 weeks gestation, as a result of intrauterine fetal death. 1 in 200 pregnancies.
Possible causes of stillbirth
- Unexplained
- Preeclampsia
- Placental abruption
- Vasa Praevia
- Cord prolapse
- Thyroid disease
Prevention of stillbirth and 3 key symptoms to always ask during pregnancy
SGA or FGR - Monitor with serial growth scans.
Give aspirin for pre-eclampsia.
3 key symptoms:
- Reduced fetal movements
- Abdominal pain
- Vaginal bleeding
How can stillbirth be diagnosed
Ultrasound to detect fetal heartbeat.
Kleihauer test if Rhesus-D negative, to check maternal blood mix. Anti-D prophylaxis dose depending on amount mixed.
Vaginal birth, either induced (mifepristone (anti-progesterone) or misoprostol (prostaglandin analogue))
What are the main signs of fetal distress
- Abnormal fetal heart rate
- Meconium stained amniotic fluid (liquor)
- Abnormal fetal scalp blood pH
- Decreased movements
- Umbilical cord prolapse
What is neonatal hypoglycaemia
Transient hypoglycaemia is common in first hours post birth
If symptomatic or very low, admit to neonatal unit and start IV 10% dextrose
what vaccines given to pregnant women
Influenza
Pertussis (from 16 weeks)
COVID also currently offered
When after delivery is contraception required?
When can POP be started, when can COCP be started, when can IUD be reinserted.
After giving birth, require contraception after day 21.
POP - Can start anytime postpartum. After day 21, use additional contraception for 2 days. (small amount of progesterone enters breast milk but not harmful.)
COCP - Contraindicated if breastfeeding <6 weeks post partum (UKMEC4). UKMEC2 if breastfeeding 6wk-6months.
- DO NOT use in first 21 days due to increased VTE risk. After day 21 use additional contraception for 7 days
IUD - Within 48 hours of childbirth or after 4 weeks
What are the risks of an inter-pregnancy interval of <12 months between birth and conceiving again
- Preterm birth
- Low birth weight
- Small for gestational age
What’s LAM
Lactational amenorrhoea method
Natural contraception, when a mother breastfeeds, it delays her periods.
3 criteria MUST be met:
- Exclusively breastfeeding
- No menstrual periods since delivery
- Babys age (less than 6 months)
LAM is over 98% effective. At 6 months, supplementary feeding starts, or cycle returns, so LAM becomes less reliable
What is an elective C section and what are some indications
Planned delivery date, usually after 39 weeks. Done under Spinal Anaethetic
Indications
- Previous C section
- Symptomatic after previous perineal tear
- Placenta and vasa praevia
- Breech
- Multiple pregnancy
- Uncontrolled HIV
- Cervical cancer
What are the 4 categories of emergency c section
1 - Immediate threat to life of baby or mother. Decision to delivery 30 mins
2 - Urgent but not imminent due to compromise of baby or mother. Decision to delivery 75 mins
3 - Delivery required but both baby and mother stable
4 - Elective, Chilling init
What is the most commonly used procedure
transverse lower uterine segment skin incision
- Pfannenstiel: Curved incision 2 fingers width above symphysis
- Joel-Cohen incision: Straight incision slightly higher (recommended)
Blunt dissection used after this to seperate remaining layers, using fingers, blunt instruments, traction. Results in less bleeding, shorter procedure, less risk to baby
Complications of C sections
Usually very safe and routine.
Surgical
- Bleeding
- Infection
- Pain
- VTE
- Damage to local structures (ureter, bladder, bowel, vessels)
- Ileus, adhesions, hernias
Postpartum
- PPH
- Wound infection
- Wound dehiscence
- Endometritis
Future pregnancy, increased risk of:
- Repeat C section
- Uterine rupture
- Placenta praevia
- Stillbirth
Contraindications to vaginal birth after c section
Normally 75% successful
- Previous uterine rupture
- Classical caesarean scar (vertical)
- Other contraindications (previous)
How is VTE prevented in C section
- Early mobilisation
- Anti-embolism stockings, intermittent pneumatic compression of legs
- LMWH
What are the types of instrumental delivery, and what are their indications, and whats given with them
Ventouse suction cup + Forceps
- Failure to progress (maternal exhaustion)
- Fetal distress
- Prolonged second stage
- Malposition
- Head in various positions
Single dose co amoxiclav given to reduce risk of maternal infection post delivery
Risks to baby in instrumental delivery
Ventouse - Cephalohaematoma (swelling on newborn head, usually parietal, doesnt cross suture lines, resolves over months)
Forcep
- Facial nerve palsy (face, ear, taste, tear)
- Face: expression muscles
- Ear: nerve to stapedius
- Taste: Anterior two-thirds of the tongue
- Tear: Parasympathetic fibres to lacrimal glands, aka salivary glands
Risks to mother in instrumental delivery
PPH
Episiotomy (cut between vagina-anus)
Perineal tears
Anal sphincter injury
Incontinence of bladder/bowel
Obturator or femoral nerve injury
Obturator - weakness of hip adduction and rotation, numbness of medial thigh
Femoral - Weakness of knee extension, loss of patella reflex, numbness of anterior thigh and medial lower leg
What indicates either of the 2 instrumentals
Ventouse - head must be partially engaged in birth canal. Works for a slightly abnormal position, as vacuum cup can sometimes rotate head.
Forcep - Preferred when rotation necessary (occiput anterior, or transverse positions)
Forcep preferred for:
- Complex rotations
- Narrow pelvic outlet
- Preterm child
What is polyhydramnios
Excessive amount of amniotic fluid
Amniotic fluid index (AFI) >25cm
OR
Single deepest pocket >8cm
Causes of polyhydramnios
Maternal
- DM, Multiple pregnancy
Fetal
- Congenital abnormalities (anencephaly, GI tract obstruction (oesophageal atresia), fetal anaemia, infections
Idiopathic half the time
How does polyhydramnios present
- Rapid uterine growth
- Maternal discomfort
- Dyspnoea
- Abdo pain
- Peripheral oedema
- May have reduced fetal movement due to excess fluid
Hows polyhydramnios investigated
- USS (measure AFI or Single deepest pocket)
- Consider detailed anatomy scan and screen for gestational diabetes
- Doppler for fetal anaemia for some reason
How is Polyhydramnios treated
Treat underlying cause + amnioreduction if extremely severe
Complications of Polyhydramnios
Preterm labour, preterm prelabour rupture of membranes PPROM, Malpresentations, Umbilical cord prolapse, PPH, placental abruption
What is vasa praevia
Where fetal blood vessels run across or near internal cervical os, unprotected by umbilical cord or placental tissue
Caused by velamentous cord insertion and succenturiate lobe.
Associated with low lying placenta and multiple pregnancy
How does vasa praevia present
Asymptomatic until membrane rupture. If vessels rupture, may present with painless, sudden vaginal bleeding during labour.
How is vasa praevia diagnosed
Routine USS with colour doppler, 18-20 weeks.
If low lying placenta or accessory lobes identified during routine anomaly scan, colour doppler used to detect vasa praevia
How is vasa praevia managed
Plan for C section 35-36 weeks.
Complications of vasa praevia
Severe fetal blood loss if rupture, leading to distress, hypoxia, death.
Rapid exsanguination is major risk! (Losing so much blood body cant function)
When is nausea and vomiting normal in pregnancy
Symptoms start 4-7 weeks, worst around 10-12 weeks, and resolve by 16-20.
What is hyperemesis gravidarum and what is thought to be the cause of morning sickness
Severe form of nausea and vomiting in pregnancy. 1% of pregnancies. Most commonly 8-12 weeks but can go up to 20.
Thought to be due to hCG, so higher levels=more sickness
RCOG criteria in hyperemesis gravidarum
- More than 5% weight loss compared to pregnancy
- Dehydration
- Electrolyte imbalance
Risk factors for hyperemesis gravidarum
- Increased HCG (Multiple pregnancy, molar pregnancy (hydatidiform mole))
- First child
- Obese
- Family or PMH of Nausea and vomiting in pregnancy
(smoking is protective fun fact)
When might nausea and vomiting need admission in pregnancy
- Continued N+V, unable to keep down liquids or oral antiemetics
- Continued N+V + Ketonuria and/or weight loss >5% body weight
- Confirmed/suspected comorbidity (e.g. unable to keep down Abx for UTI)
Medical Management of Hyperemesis Gravidarum
Medical:
- Antihistamines - Promethiazine or chloropromazine
- Phenothiazines - Prochlorperazine or chlorpromazine
- Doxylamine/Pyridoxine(B6) therapy
- Ondanestron, has slight risk of cleft lip/palate
- Metoclopramide/domperidone, can cause extrapyramidal SE, dont use for more than 5 days.
General management of Hyperemesis Gravidarum
Rehydration - Normal IV saline with added potassium
Rest and avoid triggers
Ginger
Bland plain food in morning
Complications of hyperemesis gravidarum
Dehydration
Weight loss
Electrolyte imbalance
AKI
Wernickes encephalopathy
Oesophagitis/MW tear
VTE
Drugs to avoid in breastfeeding
antibiotics: ciprofloxacin, tetracycline, chloramphenicol, sulphonamides
psychiatric drugs: lithium, benzodiazepines
aspirin
carbimazole
methotrexate
sulfonylureas
cytotoxic drugs
amiodarone
