Obstetrics Flashcards
Fertilisation to implantation?
What is blastocyst?
Fertilisation in ampulla Day 1 - fertilised Day 5 - blastocyst Day 5-8 - blastocyst attaches to endometrium Day 12 - implantation complete
Blastocyst:
- divided into 2 cell masses
- inner = embryo
- outer = trophoblast (initial progesterone and implantation, goes on to produce placenta
Placenta:
- components?
- when is it fully functional?
- functions?
- maternal cells and trophoblast cells
5 weeks
Functions:
- hormone secretion - progesterone and hCG
- gas exchange
- nutrient exchange - Ca and Fe are only 2 which go unidirectional from mother to baby
Changes and functions during pregnancy:
- hCG?
- progesterone?
- oestrogen?
hCG:
- peaks at 10 weeks then reduces
- stimulates corpus lute to produce progesterone
- ensures early nutrition of embryo
Progesterone:
- initially produced by corpus luteum then placenta
- levels steadily rise through pregnancy
- prepares and maintains endometrium
- later, decreases uterine contractions
Oestrogen:
- principal site of production is placenta
- levels steadily rise through pregnancy
- enlarges uterus, develops breasts, relaxes pelvic ligaments
E3 - indicator of foetal viability
E4 - only produced through pregnancy
CVS changes in pregnancy?
CO increases from week 6, peaks at week 24, decreases then increases again in labour
SV up 30%, HR up 15% & cardiac output up 40%
Systolic BP is unaltered
diastolic BP is reduced in the 1st and 2nd trimester, returning to non-pregnant levels by term
IVC compression causes ankle oedema, supine hypotension and varicose veins
Resp changes in pregnancy?
Pulmonary ventilation up 40%, tidal volume up 200ml
O2 requirements up 20% - over breathing causes low CO2
-> this may cause sense of dyspnoea, accentuated by diaphragm compression
Metabolic changes in pregnancy?
BMR up 15%, probably due to thyroid or adrenalcorticotrophic hormones
Haem changes in pregnancy?
Blood volume up 30% but cells less than plasma, causing relative anaemia
Rise in fibrinogen and clotting factors, increased DVT risk, esp with IVC compression
Lower platelet count
Urinary changes in pregnancy?
GFR, renal blood flow increased
Urinary protein loss increased
Salt and water reabsorption increased due to increased sex steroid levels
Calcium changes in pregnancy?
Significantly increased requirements, esp in 3rd trimester with lactation
Ca is transported to foetus through placenta
Serum levels of Ca and PO4 drop due to fall in protein, but total ionised calcium remains the same
Gut absorption of Ca increases significantly due to increased VitD activity
Uterine changes?
100g -> 1100g
Hyperplasia and later hypertrophy
Increased cervical ectropion and cervical discharge
Braxton Hicks - practice contractions late in pregnancy
Hormones in labour?
Ferguson reflex?
Progesterone - prevents contractions
Oestrogen - stimulates contractions
Oxytocin - stimulates contractions and prostaglandin release
PG - increases contractions
Ferguson reflex:
- positive feedback loop
- stretch of cervix causes release of oxytocin which causes further stretching of cervix
Gestational diabetes diagnosis?
Management?
If metformin not tolerated?
Aims once on meds?
Diagnosis:
- fasting 5.6+
- 2 hours OGTT 7.8+
Management:
- Fasting 5.6-7: diet/exercise
If no better after 1-2 weeks - metformin
if still no improvement, short-acting insulin
- If 7+ at diagnosis, insulin straight off the bat
Glibenclamide
Aims:
- fasting 5.3
- 1 hour 7.3
- 2 hour 6.4
When should foetal movements be felt?
What is reduced foetal movements?
Ix?
24 weeks - if not then refer to foetal medicine unit
- Usually start at 18-20 weeks and gradually increase to 32 weeks then plateau
- No definition but generally <10 movements in 2 hours past 28 weeks
Ix:
- handheld doppler 1st line
- If <28 weeks, just confirm presence of heartbeat, if not present then immediate referral
> 28 weeks:
- If present on doppler, do CTG for 10 mins
- If not present on doppler or still concern after CTG, do immediate USS
Supplements in pregnancy?
VitD 400IU throughout pregnancy
Folic acid for first 12 weeks
400mcg
5mg if:
- obese >30 BMI
- FHx neural tube defect
- coeliac, diabetes, thalassaemia
- alcohol excess, phenytoin, methotrexate
Variable decelerations means?
Indicates?
Rapid fall in foetal HR with variable recovery phase
Indicate cord compression and potential cord prolapse
- Elevate presenting part either manually or by filling urinary bladder
- Get on all fours
- Consider tocolysis and prep for C-sec
Management of placental abruption <36 weeks and >36 weeks?
<36 weeks:
- foetal distress on CTG - immediate C-sec
- No foetal distress - admit for tocolysis and steroids
> 36 weeks
- immediate Csec
What is pre-eclampsia?
Features of severe?
- RF?
- New onset HTN >140/90 past 20 weeks gestation
Plus one of: - proteinuria (ankle oedema)
- Organ involvement (renal, liver, haem, neuro, uteroplacental dysfunction)
Severe:
- Hypertension >160/110
- protein ++/+++
- Headache
- visual disturbance
- papilloedema
- RUQ/epigastric pain
- Hyperreflexia
- HELLP
RF:
- HTN normally of in prev preg
- CKD
- Diabetes
- autoimmune
- Primi
- > 40
- Preg interval 10 years
- BMI >35
- FHx
- Multiple preg
How to prevent pre-eclampsia?
Referral?
Management of pre-eclampsia?
75mg aspirin from 12 weeks on if 2+ RF
- Emergency secondary care assessment in any suspected
- If BP >160/110 usually admitted for observation
Drugs:
- labetalol 1st line (CI asthma)
- Nifedipine 2nd line
- Hydralazine
- Methyldopa (CI depression)
Fluid restriction may be
What is HELLP?
Management?
Presents with nausea, vomting, RUQ pain in 10-20% with severe pre-eclampsia
Haemolysis
Elevated liver enzymes
Low platelets
Delivery
What is eclampsia?
Management and comps?
How long treat for?
Seizures due to pre-eclampsia
Management:
- Magnesium both prevents and treats seizures
- Monitor urine output, resp rate and O2 sats
- Calcium glutinate treats Magnesium induced resp depression
- treat for 24 hours after delivery or after last seizure
Management of shoulder dystocia?
- McRobert’s - maximally flex and abduct hips
- Suprapubic pressure in McRobert’s
- Episiotomy (may help but allows extra room for internal manoeuvres)
- Rubin, push on posterior shoulder
- Wood’s screw, zavanellib, symphesiotomy, emergency CS
Placenta praaevia?
Normally picked up on 20 week scan
If low lying, repeat USS at 34 weeks
Suspect if painless vaginal spotting that starts >30 weeks and increases in frequency and volume
TVUS
CS to prevent labour
What is routinely offered in screening at booking scan?
- anaemia
- bacteriuria
- Blood group, rhesus, ABO
- Trisomy
- Foetal anomalies
- HepB
- HIV
- Syphilis
- neural tube defects
- RF for pre-eclampsia (diabetes, CKD, autoimmune etc)
What is placenta accreta?
RF?
Small print but different types?
Defect in decidua basalis causing placenta to attach to myometrium, risk of significant PPH as it doesn’t detach properly
Decidua basalis is the endometrial cells of the placenta, normally there is a fibrinous layer separating this from normal uterine wall
RF:
- previous CS
- placenta praevia
Accreta - chorionic villi attach to myometrium instead of decidua basalis
Increta - Chorionic villi invade myometrium
Percreta - Chorionic villi invade through perimetric
When is nuchal scan performed?
What does increased thickness mean?
11+3 - 13+6
Trisomy
Congenital heart defect
Bowel wall defect
Hyperechogenic bowel:
CF
Down’s
CMV infection
When is combined test done, what is the results?
Quadruple test?
If these come back high risk?
11-13+6 weeks
- increased nuchal translucency
- Increased bHCG
- decreased PAPP-A
If between 15-20 weeks - quadruple test:
- increased inhibin-A
- increased bHCG
- decreased AFP
- decreased unconjucated oestriol
CVS - 10-13 weeks
2% risk miscarriage
Amniocentesis - 15 weeks
1% risk miscarriage
Sample may not be adequate
Trisomy 21?
Trisomy 18?
Trisomy 13?
Down’s:
- appearance, learning disability, AVSD, duodenal atresia/Hirshprung’s, leukaemia, thyroid, epilepsy, alzheimers
18 - Edwards:
- Cardiac, GI, uro abnormalities
- Severe mental disability
- Die soon after birth
12 - Patau
- cleft palate, microcephaly
- severe mental disability, die soon after birth
How to measure foetal size?
What is SGA and LGA?
Examination - SFH USS: (- crown rump length if early) - femur length - head circumference - abdo circumference Final 3 measurements put into Hadlock equation
SGA - SFH <2cm Gest age after 20 weeks
LGA >2cm
Causes IUGR - maternal, foetal and utero-placental?
Symmetrical/asymmetrical reductions?
Complications in pregnancy, neonatal and lateral life?
Maternal:
- poor nutrition
- alcohol, smoking, drugs
- HTN, diabetes, anaemia,
- B-blockers
Foetal:
- multiple pegnancy
- congenital/chromosomal abnormality
- toxoplasma/CMV
Placental:
- pre-eclampsia
- uterine malformation
- placental insufficiency
If reduced head and abdo size suggests growth restrictions throughout pregnancy
If asymmetrical growth suggests growth reduction has occurred later in pregnancy due to placental insufficiency
Still birth/preterm labout
Jaundice, neonatal sepsis
Later life: obesity, HTN, T2DM
Causes LGA?
Diabetes Wrong dates Polyhydramnios Multiple pregnancy Constitutionally large
Drugs to avoid in breastfeeding:
- abx?
- psych?
- endocrine?
- cardiac?
- others?
abx: cipro, tetracyclines, chloramphenicol, sulphonamides (co-trimox, but trimethoprim safe)
psych: lithium, benzos, clozapine
endocrine: sulfonylurea, carbimazole
Cardiac: ACEI, amiodarone
Others: aspirin, naproxen, methotrexate, cytotoxic
Varicella exposure in pregnancy?
If develop chickenpox?
(rules for <20 and >20 weeks for both)
If any doubt, check antibodies
If <=20 weeks and NOT immune, offer IVIG within 10 days
If >20 weeks and NOT immune, wait until 7 days post-exposure and give IVIG or aciclovir for 7 days
If chickenpox:
If >=20 weeks, oral aciclovir with within 24 hours of onset
If < 20 weeks, aciclovir should be considered with caution
Management of PPH?
Initial - lie flat give O2, assess 4T’s, blood X match, rapid IV fluid replacement
- Rub uterus/bimanual palpation
- Oxytocin +/- ergometrine IM (avoid ergometrine in HTN)
- Tranexamic acid 1g slow infusion
- Oxytocin infusion (over 4 hours)
- urinary catheter
- Carboprost IM - every 15 mins up to 8 doses
- Misoprostol PR
Theatre:
- Balloon tamponade
- B-lynch sutures
- Arterial ligation
- hysterectomy
How to differentiate intrahepatic cholestasis from AFL of P?
How is each managed?
What else can cause itch in pregnancy?
Jaundice?
Cholestasis:
- pruritus palms, soles, abdo
- jaundice in 20%
- small raised bili and cholestatic enzymes
Rx: induce labour at 37 weeks (risk of still birth)
Symptomatic - Ursode acid
VitK supplements
AFL of P:
- RUQ pain, vomiting
- Jaundice
- Headache
- Hypoglycaemia
- Severe disease may cause pre-eclampsia
- ALT >500
Rx: stabilise and delivery
Itch: Prurigo of pregnancy - itchy papular rash over abdo and legs >35 weeks - creams and delivery
Jaundice:
- HELLP
- Gilbert’s can flare
Differentiating between ITP and gestational thrombocytopaenia?
Why can it be important?
Difficult - usually if low platelets at booking scan or previous ITP will be tested for anti-platelet antibodies
If slow progression of decreased platelets gestational TCP presumed, but if dangerously low then ITP presumed and given steroids
Gest TCP doesn’t affect newborn, but ITP can cause TCP in newborn as IgG crosses placenta - can cause haemorrhage in newborn - high risk if prolonged ventouse
Pathophysiology of RhD disease?
Sensitisation events?
If Rh- mother has Rh+ baby, this causes anti-D IgG to form.
This usually happens in first pregnancy as blood mixes during delivery. This causes IgG to cross placenta in future pregnancies
In first pregnancy this can also occur due to sensitisation events.
Sensitisation events:
- giving birth
- previous TOP
- miscarriage >12 weeks
- ectopic managed surgically
- antepartum haemorrhage
- amnio/CVS/foetal blood sampling
- external cephalic version
- abdo trauma
When to give anti-D?
What to do after sensitising events?
If woman is already sensitised?
Test all Rh- women for anti-D at booking - indirect coombs test (indirect antiglobulin)
Give anti-D to all non-sensitised Rh- women at 28 and 34 weeks
After a sensitising event:
- <20 weeks give 250 units anti-D
- > 20 weeks give 500 units and Kleihauer (tests for quantity of foetal blood in maternal circulation)
If already sensitised nothing can be done unfortunately
If woman has anti-D antibodies what will happen?
Cross placenta and cause Rhesus haemolytic disease - spectrum
- progressive anaemia
- CCF
- hepatosplenomegaly
- bilirubin -> kernicterus
- hydrops fetalis
(hydrops - oedematous as albumin falls because liver devoted to RBC production)
If foetus still viable, can deliver if appropriate gestation, and transfuse once born and give phototherapy
Risk factors for abruption?
- Proteinuria/HTN/pre-eclampsia
- cocaine abuse
- polyhydramnios
- multiparity
- trauma
- increasing maternal age
Presentation of abruption?
Lower abdo pain May be some blood Usually pain out of proportion with findings Tender, hard uterus May have shock - anuria/DIC/tachy/hypo
If >36 weeks - emergency CS
If <36 weeks check CTG
- distress - emergency CS
- no distress yet - admit for steroids
Amniotic fluid embolism:
- presentation?
- test?
- Rx?
Usually in labour, can happen in CS or immediate postpartum period as well
Essentially same as PE
Dyspnoea, coughing, chest pain, tachycardia, tachypnoea, hypotension, cyanosis, arrhythmia
No definitive test, diagnosis of exclusion
ICU MDT, mainly supportive
Suspected DVT/PE in pregnancy:
- Ix DVT?
- Ix PE?
- Rx?
- thrombolysis?
DVT: Duplex USS
PE:
- ECG and CXR
- If DVT, duplex USS - if present treat (no need for CT/VQ)
- if no DVT, decision between CTPA/VQ is with radiologist and pt
CTPA - higher dose radiation to mother, risk breast cancer
VQ - higher dose radiation to baby, risk childhood cancer
D dimers useless as raised in pregnancy
Rx: LMWH (DOAC and Warfarin CI in pregnancy)
Thrombolysis also CI in pregnancy as it will result in catastrophic haemorrhage for mother and foetus
Most common cause of cord prolapse?
Artificial rupture of membranes
3/4 commonest pregnancy-related causes of bleeding in each trimester?
Maternal causes for any trimester?
1st:
- implantation
- spontaneous abortion
- ectopic pregnancy
- mole
2nd:
- abortion
- mole
- abruption
3rd (antepartum haemorrhage):
- bloody show
- abruption
- placenta praevia
- vasa praevia
Maternal:
- genital tract infection
- Cervical ectropion, polyp or malignancy
When is Hb checked in pregnancy?
If Fe depleted?
Booking, 28 and 34 weeks
200mg ferrous sulphate
Types of miscarriage:
- complete?
- incomplete?
- missed/delayed?
- anembryonic pregnancy?
- threatened?
- inevitable?
Complete - empty uterus
Incomplete - pain and bleeding, some products of conception still there, os open, some have been expelled
Missed/delayed - some light spotting/no bleeding at all - dead foetus, os closed
Anembryonic pregnancy - gestational sac >25mm but no foetal parts
Threatened - painless bleeding <24 weeks, os closed, pregnancy continues
Inevitable - some bleeding with clots and pain, os open, miscarriage about to happen
1st line management for miscarriage?
Criteria for intervention?
Medical management?
Surgical management?
Expectant - wait 14 days
Criteria:
- Increased risk of haemorrhage (late 1st trimester or coagulopathy)
- signs of infection
- previous adverse/traumatic experience
Medical:
- Oral misoprostol
- give anti-emetics and analgesics
Surgical:
- vacuum aspiration (LA, outpatient)
- surgical evacuation (GA, inpatient)
How to diagnose miscarriage?
Can diagnose if sac >25mm or CRL >7mm and no heartbeat, but need 2 sonographers to confirm
If <25mm or <7mm cannot diagnose on first scan - pregnancy of uncertain viability - need to wait a week and rescan
What is needed for TOP? How is it done if: - <9 weeks (early)? - 9-12 weeks (late)? - 12-14 weeks (mid-trimester)?
- 2 medical practitioners to sign off on it
- in emergency only one is needed (risk to life)
Method:
<9 weeks - mifepristone (progesterone antagonist) followed by misoprostol 48 hours later - this can be completed at home
9-12 weeks - vacuum aspiration
> 12 weeks - medical - in hospital
If someone has discharge very early e.g. 25 weeks, how can you test if it is from gestational sac?
What should you do?
foetal fibronectin test of fluid in speculum test
Admit for 2 doses of steroids in case of preterm labour
What is someone with insulin-controlled diabetes e.g. T1DM needs 2 high dose steroids IM?
Admit and monitor BM’s closely, adjusting insulin accordingly
Group B strep: RF for infection? If GBS in previous pregnancy? To women in preterm labour? If fever in labour?
20-40% of women are carriers
RF:
- prematurity
- PPROM
- Previous GBS sibling
- Maternal pyrexia (chorioamnionitis)
If GBS in prev pregnancy they should be offered intrapartum benzylpenicillin or testing 3-5 weeks before delivery (and Rx if +ve)
Intrapartum abx should be offered to ALL women in preterm labour regardless of GBS status
Offer intrapartum abx to ALL women with temp >38 in labour
Baby blues?
Postnatal depression?
Puerperal psychosis?
Baby blues:
- affects 60% women, first 3-7 days following birth, anxious, tearful and irritable
Postnatal depression:
- affects 10%
- Symptoms start in first month and peak at 3 months
- Support, CBT
- Sertraline and Paroxetine only ones licensed
Puerperal psychosis?
- affects 0.2%
- onset first 2-3 weeks following birth
- severe mood swings (similar to bipolar), disordered perception (auditory hallucinations)
- 25-50% chance of reoccurrence in future pregnancies
What vaccines are live attenuated and so cannot be given in immunodeficiency/pregnancy?
MMR Varicella Yellow fever Rotavirus Influenza
Maternal indications for inducing labour?
- Prolonged pregnancy >41 weeks
- PPROM
- Hypertension, diabetes, cholestasis, APH, deteriorating illness
Foetal:
- macrosmia
- IUGR
Contraindications for inducing labour?
Malpresentation
Praevia
Cord prolapse
Signs of foetal distress
What foods to avoid in pregnancy?
Travel?
Sports?
Listeriosis:
- unpasteurised milk, soft cheeses (camembert, brie, blue), pate
Salmonella:
- undercooked meat/poultry/eggs
Vit A:
- Liver (teratogenic)
Air travel:
Avoid >37 weeks in singleton pregnancies and >32 in multiple pregnancies - wear compression stockings
Sports:
Avoid high impact sports and scuba diving
PPROM:
- complications?
- how to determine?
- management?
Comps:
foetal - prematurity, infection, pulmonary hypoplasia
maternal - chorioamnionitis
Determine:
- sterile speculum exam to look for pooling of fluid in posterior vaginal vault
- Avoid digital exam - risk of infection
- If no pooling but suspicion, USS to look for oligohydramnios
Management:
- admit
- regular obs to ensure no chorioamnionitis
- Erythromycin 10 days
- Steroids
- Consider delivery at 34 weeks
