OBS - pregnancy & labour/birth Flashcards
Obstetrics
Definition: Prematurity
Onset of labour before 37 weeks gestation
- < 28 weeks: Extremely preterm
- 28-32 weeks: Very preterm
- 32-37 weeks: Moderate to Late preterm
What are the 4 phases of cervical remodelling?
- Softening
- Ripening
- Dilation
- Repair
What is the aetiology of preterm birth?
- Term labour results from physiological activation of the pathway
- Preterm labour results from pathological processes that activate one or more components of the common pathway
Name 4 causes of preterm birth
- Infection - most common
- Ischaemia
- Uterine overdistension
- Cervical disease - cervical weakness
What are two preventative measures for preterm birth?
Given to women with a cervical length < 25mm between 16 and 24 weeks gestation / had previous preterm birth
- Progesterone- daily vaginal suppositories
- Cervical cerclage: stitch into the cervix
What is done to determine when management can be offered to treat a preterm?
< 30 weeks gestation
* clinical assessment alone is enough
> 30 weeks gestation:
- Cervical length screening (< 15)
- Foetal fibronectin
What is the management of a preterm labour?
- Tocolysis: stop uterine contractions (Nifedipine or atosiban)
- Antenatal steroids: 2 IM betamethasone injections 24 hrs apart, reduces neonatal mortality, reduces NEC
- IV magnesium sulphate: protects baby’s brain, reduces risk of cerebral palsy
-
Delayed cord clamping: increases circulating blood vol & Hb
-intrapartum antibiotics - to stop group B strep infections
-thermoregulation
Definition: Prelabour rupture of membranes (PROM)
Rupture of membranes after 37 weeks gestation
Definition: Preterm prelabour rupture of membranes (P-PROM)
Amniotic sac has ruptured before onset of labour and before 37 weeks gestation, releasing amniotic fluid
How is preterm prelabour rupture of membranes diagnosed?
Speculum exam - shows pooling of amniotic fluid in vagina
If in doubt:
* Insulin-like growth factor-binding protein-1 (IGFBP-1): protein in amniotic fluid
* Placental alpha-microglobin-1 (PAMG-1)
What is the management of preterm prelabour rupture of membranes?
- Prophylatic antibiotics: prevent chorioamnionitis (erythromycin)
- Induction of labour: from 34 weeks
What is a low birth weight infant defined as?
Born with birthweight < 2.5kg (regardless of gestational age)
What is a very low birth weight infant defined as?
Babies weighing < 1.5kg
What is an extremely low birth weight infant defined as?
Babies weighing < 1kg
How do you manage a low birth weight infant?
- NICU
- Temp-controlled bed
- Special feeding: tube in stomach/IV
What are some common problems of low birth weight babies?
- Low O2 levels at birth
- Trouble staying warm
- Trouble feeding/gaining weight
- Infection
- Breathing problems
- Nervous system problems, e.g. haemorrhage
- Digestive problems e.g.necrotising enterocolitis
- sudden infant death syndrome (SIDS)
What are some long-term complications of of being a very low birthweight baby?
- Cerebral palsy
- Blindness
- Deafness
- Developmental delay
What is placental insufficiency?
- Oxygen/nutrients are not sufficiently transferred to the foetus via placenta during pregnancy
- Leads to foetal hypoxemia & restricted foetal growth
What causes placental insufficiency?
- Disturbances to perfusion of placenta
- Reduction in surface area of placenta that becomes integrated in uterine walls
- Placentation can be negatively affected by lateralisation (placenta favours one side instead of being implanted centrally): blood isn’t equally distributed = distribution of nutrients affected
What is gestational diabetes
diabetes triggered by pregnancy due to reduced insulin sensitivity which resolves after birth
Complications of gestational diabetes (3)
Large fetus + Macrosomia (large newborn)
Shoulder dystocia - during birth
Maternally
Higher risk of developing type two diabetes after pregnancy
Risk factors for gestational diabetes (5)
-Previous gestational diabetes
-Previous macrosomic baby (≥ 4.5kg)
-BMI > 30
-Ethnic origin (black Caribbean, Middle Eastern and
South Asian)
-Family history of diabetes (first-degree relative)
-polycystic ovarian syndrome
Screening test for gestational diabetes
Oral glucose tolerance test
What features suggest gestational diabetes? (3)
-Large for date fetus
-Polyhydramnios
-Glucose on urine dipstick
How is oral glucose to test carried out?
-In the morning after a fast
-Drink 75 g of glucose
-Blood sugar levels are measured before and 2 hours after
What are normal results for OGTT
Fasting <5.6 mmol/L
2 hours after glucose < 7.8 mmol/L
remember 5-6-7-8
Mx of gestational diabetes
4 weekly ultrasound scans - measure amniotic fluid volume and fetal growth for macrosomia
Fasting glucose less than 7 mmol/l -
- trial of diet and exercise for 1-2 weeks
- followed by metformin
- then insulin
Fasting glucose above 7 mmol/l - start - insulin ± metformin
Fasting glucose above 6 mmol/l plus macrosomia (or other complications) - -start insulin ± metformin
What is given to women with gestational diabetes who can’t tolerate metformin
Glibenclamide (a sulfonylurea)
What’s the measures done for those with pre existing diabetes (5)
Pre conception
-5mg folic acid
Aspirin 150mg daily from 12 weeks - reduce pre eclampsia
During pregnancy
Women with pre existing diabetes still want same insulin levels as in gestational diabetes
Retinopathy screening - check for diabetic retinopathy
Planned pregnancy at 37-38+6 weeks with pre existing diabetes
Sliding scale insulin regime - with type 1 diabetes/poorly controlled type 2/ gestational
Postnatal care of gestational diabetes for:
Women with gestational diabetes
Women with pre existing diabetes
Babies
Women with only gestational diabetes
Stop medication immediately
Women with existing diabetes
Lower insulin doses to avoid hypoglycaemia
Pre pregnancy counselling
Babies
-neonatal hypoglycaemia - regular BG tests + frequent feeds
-IV dextrose or nasogastric feeding if blood sugar below 2
What is an antepartum haemorrhage
•Bleeding from anywhere within the genital tract after the 24th week of pregnancy
Causes of Antepartum haemorrhage (4)
-low lying placenta/ placenta praevia
-vasa praevia
-minor/major abruption
-infection
What is low lying placenta
Any part of the placenta that has implanted into the lower segment of the uterus
What classes as a major and minor low lying placenta
Major - covering the Os
Minor - in lower segment not covering os
How to diagnose low lying placenta
20 week Ultrasound scan
Repeated at 32 weeks + 36 weeks
Mx of low lying placenta
•Advise to present if pain / bleeding
•Advise to avoid sexual intercourse
•If recurrent bleeds may require admission until delivery and ensuring has cross-match in date
•Remember to give anti-D if Rh negative
•Elective Caesarean section around 37/40
What is placenta praevia?
When the low-lying placenta partially/completely covers opening of cervix
Signs and symtoms of placenta praevia
-painless vaginal bleeding
-light contractions
-lie and presentation of baby maybe abnormal
What is placental abruption
the complete or partial detachment of the placenta before delivery.
Cause of placental abruption
Unknown
Maybe trauma or injury
Risk factors of placental abruption
-maternal aged 35+
-Multiparity (e.g twins)
-pre eclampsia
-smoking during pregnancy
-use of cocaine during pregnancy
-trauma
-Hx of HTN
-Hx of anti phospholipid syndrome
Clinical presentation of placental abruption (5)
-Abdominal pain (most common) – posterior
-placental abruptions may present with back pain
-Vaginal bleeding
-Uterine contractions
-Dizziness and/or loss of consciousness
Clinal findings upon examination for placental abruption
-woody, tense uterus
-fetal heart may be absent or distressed
Investigations for placental abruption
Diagnostic - ultrasound scan to locate the bleed
Other
-vital signs
-FBC
-Clotting profile
-kelihauer test - fetal haemoglobin transferred from fetus to mother
Mx of placental abruption
Foetus alive
-fetal distress - immediate C-section
-no fetal distress - observe closely
Foetus dead - induce signal delivery unless mother heamodynamically unstable - then do C-section
Complications of placental abruption in:
Mother
Foetus
Complications in mother:
-Major haemorrhage
-Shock: can result in Sheehan syndrome - pituitary gland necrosis
-Compression of uterine muscles prevents good contraction of muscles during labour
-disseminated intravascular coagulation (DIC)
-Post-partum haemorrhage
Complications for the fetus:
Placental insufficiency: results in hypoxia and intrauterine growth restriction (IUGR) due to lack of nutrients
-Premature birth
-Stillbirth
What is vasa praevia
Fetal blood vessels (the two umbilical arteries and single umbilical vein) are within the fetal membranes and run across the internal cervical os.
Risk factors for vasa praevia (3)
IVF pregnancy
Multiple pregnancy
Low lying placenta
Sx of vasa praevia
-Painless vaginal bleeding
-Rupture of membranes
-Fetal bradycardia
Investigations for vasa praevia
Diagnostic - ultrasound scan
Others:
Vital signs
FBC
Clotting profile
Kleihauer test
Mx of vasa Praevia (3)
-if found on US then elective casearean section at 34-36 weeks
-corticosteroids given to promote fetal lung maturity
If Antepartum haemorrhage then emergency caesarean
What is pre eclampsia
New high blood pressure in pregnancy with end organ dysfunction usually with proteinuria
Triad of pre eclampsia
Oedema
Proteinuria
Hypertension
Whats the pathology of pre eclampsia
after 20 weeks gestation, when the spiral arteries of the placenta form abnormally (more tangled), leading to a high vascular resistance in these vessels and poor perfusion of placenta.
Leads to oxidative stress in the placenta
Release of inflammatory chemicals into systemic circulation and impaired endothelial function of blood vessels
What is eclampsia
When seizures occur as a result of pre-eclampsia.
What is gestational HTN
Hypertension occurring after 20 weeks gestation, without proteinuria.
High Risk factors for pre eclampsia (5)
Pre existing HTN
HTN before in pregnancy
Existing autoimmune conditions e.g lupus
Diabetes
CKD
Treatment of eclampsia (2)
Deliver baby after mum is stabilised
-IV MgSO4 for 24 hours
-Treat HTN - labetelol or nifedipine
Risk factors 5 for maternal sepsis (10)
-obesity
-diabetes
-anaemia
-history of pelvic infection
-history of group strep B infection
-group A strep infection
-immunosuppressant meds
-PROM
-vaginal discharge
-amniocentesis
Maternal sepsis management
Within first hour sepsis 6
•1) O2 as required to achieve SpO2 over 94%
•2) Take blood cultures
•3) Commence IV antibiotics
•4) Commence IV fluid resuscitation
•5) Take blood for Hb, lactate (+glucose)
•6) Measure hourly urine output
Stabilise mother then deliver baby
What is cord prolapse
umbilical cord descends below the presenting part of the fetus and through the cervix into the vagina, after rupture of the fetal membranes
Main complication of cord prolapse
Fetal hypoxia
Biggest risk factor for cord prolapse
fetus is in an abnormal lie after 37 week gestation as it allows room for cord to descend
How to diagnosis cord prolapse (3)
-CTG showing signs of fetal distress
-vaginal examination
- speculum
Management of cord prolapse + cord compression
Cord prolapse
-Emergency C- section
If cord compression
1) push presenting cord upward to prevent compression
2) Positions:
-put woman in left lateral position
-on all fours (gravity reduces compression)
3) medication:
-terbutaline (tocolytic - minimises contractions)
What is umbilical cord compression
Babies umbilical cord becomes flattened by pressure leading to vasoconstriction and fetal hypoxia due to lack of oxygenated blood
What is hyperemesis gravidarum
Exhaggerated, long in duration, nausea and vomiting in early pregnancy
What weeks does hyperemesis gravidarum usually occur
4-8 weeks of gestation
Causes of hyperemesis gravidarum
-rapidly rising HCG levels
-pregnancy related decreased gastric motility
Risk factors of hyperemesis gravidarum
-previous hyperemesis gravidarum
-increased hCG levels
-multiple pregnancy
-biologically female foetus
-hyperthyroidism
Complications for hyperemesis gravidarum
-dehydration
-weight loss
-Mallory Weiss tear
-metabolic alkalosis
-electrolyte imbalance
If prolonged
-intrauterine growth restriction
Signs and symptoms of hyperemesis gravidarum
-frequent N+V
-signs of dehydration- tachycardia, palpitations, hypotension, decreased skin turgor
-malaise
-increased sensitivity to smell
-weight loss
-ketoacidosis odour - pear drops
How to diagnose hyperemesis gravidarum
Pelvic ultrasound - to exclude molar pregnancy + identify multiple pregnancy
Lab results
-blood urea nitrogen - increased
-creatinine - increased
-potassium - decreased
-sodium - decreased
-urinalysis - increased ketones
excessive vomiting history - clinical dehydration signs
Tx of hyperemesis gravidarum (3)
-Antiemetics
-Vitamin B6 - decreases nausea
-Fluid, electrolyte replacement
Trigger avoidance
-small, frequent meals
-avoid spicy food
What is placenta accreta
Placenta implants deeper, through and past the endometrium - makes it hard to remove the placenta after delivery
What are the three layers of the uterine wall
Endometrium - inner layer - connective tissue layer
Myometrium - middle layer - smooth muscle layer
Perimetrium - outer layer - serous membrane
What are the three levels of severity of placenta accreta
superficial placenta accreta - placenta implants in the myometrium
placenta increta - placenta attaches deeply to the myometrium
placenta percreta- placenta invades into perimetirum and can reach other organs
Management of placenta accreta
C-section 35-36 weeks gestation to reduce spontaneous delivery
Surgery
-hysterectomy - preserving the placenta
-uterus preserving surgery - resection of part of the myometrium and the placenta
-expectant management - leaving the placenta to be reabsorbed over time
antenatal steroids for fetal lung maturation
How to diagnose placenta accreta
Ultrasound - allows for planning
MRI scans - assess depth and width
What is uterine rupture
A complication of labour where the myometrium layer of the uterus ruptures
What’s the difference between complete and incomplete uterine rupture
Complete - the perimetrium also ruptures so the content of the uterus is released into the peritoneal cavity
Incomplete - the perimetrium remains in tact
5 Risk factors for uterine rupture (7)
-having a vaginal birth after a C section (VBAC)
-previous surgery on uterus
-induction of labour
-high parity (number of times they have given birth to live baby)
-increased BMI
-increased age
-using oxytocin to stimulate contractions
Presentation of uterine rupture
-Abnormal CTG
-abdo pain
-vaginal bleeding
-ceasing of uterine contractions
-hypotension
-tachycardia
-collapse
What is the treatment of uterine rupture?
!!Obstetric emergency!!
* Resuscitation & transfusion may be required
* Emergency C section necessary to remove baby, stop bleeding & repair/remove uterus
What is cervical show?
‘Show’ is a blood-stained discharge from uterus, often mixed with mucus
How does cervical show originate?
- Slow cervical dilation in early labour
- Causes loosening & expulsion of thick mucus plug that blocks the cervical canal throughout normal pregnancy
Definition: postpartum haemorrhage
Bleeding after delivery of the baby and placenta. With blood loss of:
1000ml in C section
500ml in normal delivery
What is a major haemorrhage and what are the two classifications
Major PPH is anything ABOVE 1000ml blood loss
Further classified into:
Moderate PPH - 1000-2000ml blood loss
Severe PPH - over 2000ml blood loss
What are primary and secondary PPH
Primary - bleeding within the first 24 hours of delivery
Secondary - bleeding from 24 hours to first 12 weeks after birth
4 causes of postpartum haemorrhage
T – Tone (uterine atony – the most common cause)
T – Trauma (e.g. perineal tear)
T – Tissue (retained placenta)
T – Thrombin (bleeding disorder)
Give 5 risk factors for PPH
-previous PPH
-multiple pregnancy
-obesity
-large baby
-pre eclampsia
-placenta accreta
-placenta retained
-instrumental delivery
-general anasesthesia
-episiotomy or perineal tear
How do you prevent a PPH (4)
-treat underlying anaemia during the antenatal period
-giving birth with an empty bladder ( as with a full bladder it reduces uterine contractions)
-IM oxytocin during third stage of labour - promotes contractions
-IV tranexamic acid used during C section in higher risk patients
Initial Mx of PPH
obstetric emergency
-ABCDE resuscitation
-woman lay flat and kept warm
-insert TWO large bore cannulas to take Bloods for FBC, U+E, clotting screen
-group and cross match (blood transfusion)
-warmed IV fluid and blood resuscitation
-oxygen
-fresh frozen plasma if clotting abnormalities (DIC)
Management of PPH if cause is atony (6)
Initial MX steps and then in sequence:
bimanual uterine compression to manually stimulate contraction
intravenous oxytocin and/or ergometrine
intramuscular carboprost
intramyometrial carboprost
rectal misoprostol
surgical intervention such as balloon tamponade
What the Mx of PPH if cause is thrombin is cause
Tranexamic acid
Vitamin K ( discuss with haematology)
Fresh frozen plasma
Most common cause of secondary PPH (2)
Endometritis - inflammation of the uterine endometrium
Retained products of conception e.g placenta