Obstetrics Flashcards
Placental Abruption
Separation of the placenta from the uterine wall, bleed into the space
= shock ≠ visible loss, constant pain, tender tense uterus, normal lie and presentation
Inv - distressed/ absent foetal HR
-> immediate c-section if distressed, if not observe + steroids <36wks or vaginal >36wks, induce vaginal if dead
Comp - shock, DIC, renal failure, PPH
Abruption: RF
A - Abruption before
B - Blood pressure
R - Ruptured membranes, prolonged or premature
U - Uterine injury/ trauma
P - Polyhydraminos, previous children
T - Twins
I - Infection
O - Old age
N - Narcotics (cocaine)
Placenta Praevia
Placenta lying in the lower uterine segment, risk of PPH
RF - multiparity, multiple pregnancy, prev C section
= shock ≈ loss, no pain, uterus not tender
Inv - DON’T DO PV exam, abdo US (incidental), TV US
-> if low at 20wks then rescan at 32wks, still present scan every 2 weeks, decide on delivery at 36-37wks, elective c-section for 3/4 (emergency c-section if labour before/ unstable or term bleeding)
- placenta reaches lower segment but not os
- reaches os but doesn’t cover it
- covers the os before dilation
- placenta completely covers os
Down’s Syndrome Screening
Combined test (11-14wks) - ^hCG, v PAPPA-A, thick nuchal translucency (US) thickened US
*Lower hCG in Edwards and Patau
Quadruple test (15-20wks) - ^inhibin A, ^hCG, v AFP, v oestriol
‘higher chance’ offered NIPT (99% spec/sens) or amniocentesis/ CVS
AFP
Protein produced by developing foetus
Increased in NTD, abdo wall defects, twins
Decreased in downs, edwards (18), maternal DM
Quadruple Test
AFP, uc Oestriol, HCG, Inhibin A
Downs - low, low, high, high
Edwards - low, low, low, normal
NTD - high, normal, normal, normal
High chance (>1 in 150)
Preterm Prelabour Rupture of the Membranes
Inv - sterile speculum exam (pooling of amniotic fluid in post vaginal vault), avoid DVE, placental PAMG1 or insulin-like GF protein 1, US (oligohydramnios)
-> admit, 10d PO erythromycin, antenatal steroids, consider delivery at 34 weeks
Comp - premature delivery (40% linked to PPROM), pulm hypoplasia, chorioamnionitis
Management of Miscarriage
Expectant: 7-14d watch and wait, next if doesn’t work
Medical or surgical if evidence of infection, risk of bleed (late T1, coagulopathies) or prev adverse experience with pregnancy
-> Medical
Missed: oral mifepristone, misoprostol 48hrs after, see Dr if no bleed in 24 hours
Incomplete: single dose misoprostol (PV/ PO)
-> Surgery; vacuum aspiration or ERPC
*Pregnancy test at 3wks to confirm
Amniotic fluid embolism
Reaction 2nd to fetal cells/ amniotic fluid in maternal bloodstream
RF - ^age, induction of labour
= most during labour, chills, sweating, anxiety, cough, v BP, ^HR, bronchospasm, arrhythmia, MI
-> supportive, critical care unit
Antenatal timetable
8-12wks = Booking, general info, BP, BMI, urine culture, FBC, blood group, rhesus, RC alloantibodies, Hb disease, syphilis, Hep B, HIV offered
10-14wks = Dating scan and Down’s screen, excl. multiple
16wks = review prev, iron if <110, BP, urine dip
18-21wks = Anomaly scan
*BP, dip, SFH at all below
28wks = screen Hb and allo, 1st anti-D dose
34wks = 2nd anti-D dose, labour info
36wks = presentation (offer ECV), BF info
38wks = routine
41wks = info on induction
Primip also get 25wks, 31wks, 40wks
Weight gain and breastfeeding
1/10 lose the 10% threshold of weight in week 1
-> examine infant, referral to midwife-led BF clinics, monitor weight until regains
Drugs to avoid in breastfeeding
Methotrexate
Benzos
Carbimazole, chemo drugs
Lithium
Aspirin
Sulphonylureas
Sulphonamides
Amiodarone
Ciprofloxacin, chloramphenicol
Tetracycline
Breech Presentation
25% are breech at 28wks, 3% at term
RF - uterine malformation, fibroids, praevia, prem, poly/ oligohydramnios, foetal abnormality
-> offer ECV at 36wks (37wks if multiparous), plan vaginal or c-section
ECV contra if c-section required, APH in last 7d, abnormal CTG, major uterine anomaly, ruptured membranes, twins
Categories of C section urgency
1 - immediate threat to life, deliver <30 min
E.g., uterine rupture, major abruption, cord prolapse
2 - maternal or fetal compromise but not threatening life, <75 min
3 - required but both stable
4 - elective
VBAC: at 37wks+, 75% success if one previous c-section, contra if prev uterine rupture or classic C section scar
Cardiotocography (CTG)
Baseline bradycardia (<100): ^fetal vagal tone, beta blockers
Baseline tachycardia (>160): maternal fever, chorioamnionitis, hypoxia, prematurity
Loss of variability (<5): hypoxia, prematurity
Early deceleration (starts with onset of contraction, returns to normal at end of it): harmless head compression
Late deceleration (lags onset of contraction, returns >30secs after end): fetal stress e.g., asphyxia
Variable deceleration (independent of contractions): cord compression
Chickenpox in Pregnancy
Management of exposure
-> any doubt if mum has had it previously then check IgG, oral acyclovir 7-14d after exposure
Management of chicken pox:
-> specialist advice, PO acyclovir if <24hrs of rash and 20wk+ of pregnancy, consider if under 20 weeks
Comp - 5x pneumonitis in mum, fetal varicella syndrome (exposed <20wk, scars, small eyes/ head, limb hypoplasia, LD), neonatal varicella (rash 5d before- 2d after birth, 20% mort), shingles in infancy
Chorioamnionitis
Life-threatening, ascending bacterial infection of amniotic fluid/ membranes/ placenta
PF - PPROM
-> prompt delivery, IV Abx
Eclampsia
Development of seizures in association with pre-eclampsia (new proteinuria and HTN after 20wks)
-> MgSO4 (4g bolus + 1g/hr, until 24hrs from last seizure or delivery), calcium gluconate if Mg resp depression
*Monitor RR, urine output, reflexes, o2 sats
Folic Acid
Converted to tetrahydrofolate for DNA/RNA synthesis
RF - phenytoin, methotrexate, pregnancy, alcohol
-> 400mcg before conception-12wks, 5mg if high risk (F/Hx of NTD, antiepileptics, coeliac, DM, thalassaemia, BMI >30)
Comp - NTD, macrocytic megaloblastic anaemia
Gestational Diabetes
Diabetes that develops during pregnancy, 1 in 20
RF - BMI>30, prev macrosomia (4.5kg+), prev gestational DM, 1st degree relative with DM, family origin
Inv - OGTT (asap after booking if prev GDM, 24-28wks if RF)
Fasting = 5.6+, 2hr = 7.8+
-> seen in diabetic antenatal clinic <1wk, diet and exercise for 1-2wk, metformin if targets not met, add short-acting insulin (1st line if fasting 7+ or evidence of comp)
GDM Targets
Fasting - 5.3
1hr after meal - 7.8
2hr after meal - 6.4
Group B Streptococcus
Most common cause of early neonatal sepsis, e.g., Streptococcus agalactiae
RF - prem, prolonged ROM, prev baby infected, maternal fever
Inv - swabs at 35-37wks or 3-5wks before delivery
-> intrapartum Abx proph (benpen) if prev. GBSD baby or fever in labour >38, offer to any prem, IAP or testing in late pregnancy (+/- Abx) if GBS detected prev.
HELLP Syndrome
Haemolysis, elevated liver enzymes and low platelets
RF - severe pre-eclampsia (10-20% develop HELLP)
= n+v, RUQ pain, lethargy
-> deliver baby
Hep B and pregnancy
All offered screening
If born to mother with chronic infection -> full course of vaccines and hep B Ig
Safe to breastfeed
HIV and pregnancy
Screening offered to all, management based on viral load
<50 at 36wks -> vaginal delivery, PO zidovudine to neonate
> 50 -> c-section, zidovudine infusion started 4hrs before, triple ART to neonate for 4-6wks
Cannot breastfeed
HTN in pregnancy
Normal for BP to fall until 20-24wks then increase to term
RF - HTN in prev pregnancy, CKD, DM, AI disorders
Pre-existing: HTN <20wks
Pregnancy-induced: >20wks but no proteinuria or oedema
Pre-eclampsia: >20 weeks with proteinuria (>0.3g/d)
-> PO labetalol (nifedipine if asthmatic), aspirin 75mg OD 12wks-birth if high risk of pre-eclampsia
Induction of Labour
Use - prolonged pregnancy, PPROM, diabetic mother >38wks, pre-eclampsia, obs cholestasis, IU death
Bishop score: <5 unlikely to start without induction, 8+ high chance of spont labour
Options
Membrane sweep - an adjunct, 40-41wk appt
Vaginal prostaglandin E2 - dinopostone
Oral prostoglandin E1 - misoprostol
Oxytocin infusion
Amniotomy - break the waters
Cervical ripening balloon
Bishop 6 or below offer prostaglandin, >6 offer amniotomy or IV oxytocn
Comp - uterine hyperstimulation (v fetal blood supply), amniotic fluid embolisim
Intrahepatic Cholestasis of Pregnancy
= itchy palms and abdo, 20% get jaundice, ^BR
-> induce at 37-38wks, ursodeoxycholic acid
Comp - likely to recur in next pregnancy
Stages of Labour
1 - onset of true labour to fully dilated cervix
Latent phase: 0-3 cm dilation, 6hr
Active phase: 3-10 cm, 1cm/hr
2 - full dilation to delivery, passive or active (pushing), 1hr, if longer consider instruments
Oligohydraminos vs Polyhydraminos
Oligo
Causes - PROM, Potter sequence (bilateral renal agenesis, pulm hypoplasia), IUGR, pre-eclampsia or post term
Poly
Causes - maternal DM, twin-twin transfusion syndrome, twins
Perineal Tears
First degree - superficial, no muscles involved -> no repair
Second degree - perineal muscle but not anal sphincter -> suture on ward
Third degree - a) <50% external sphincter, b) >50% EAS, c) internal AS torn -> repair in theatre
4th - anal sphincter and rectal mucosa -> theatre
Placenta accreta
Attachment of the placenta to the myometrium, doesn’t separate properly during labour so ^PPH
RF - prev c-section, placenta praevia
Accreta: chorionic villi attached to myometrium (not restricted within decidua basalis)
Increta: invade into the myometrium
Percreta: through the perimetrium
PPH
Blood loss >500ml after vaginal delivery, primary <24hrs
Causes - 4Ts - tone (atony, most common), trauma, tissue retained, thrombin
RF - prev PPH, prolonged labour, pre-eclampsia, ^age, polyhydramnios, emergency c section, placental issues, macrosomia
-> A-E, rub uterine fundus to stimulate contraction, catheterise, IV oxytocin, IV/IM ergometrine, IM carboprost, surgery (IU balloon tamponade if atony)
Secondary PPH: 24hrs - 6wks, caused by endometritis or retained placental tissue
Postpartum Thyroiditis
= hyper, hypo then normal, high recurrence
Inv - anti-TPO Ab (90%)
-> propranolol for hyper, thyroxine for hypo
Pre-eclampsia
BP >140/90 after 20 weeks + one of; proteinuria or organ dysfunction
Risk Factors
High - HTN in prev pregnancy/ chronic, CKD, AI (SLE), DM
Mod - 1st pregnancy, 40yrs+, preg interval >10yrs, BMI 35+, multiple pregnancy, FHx
= HTN, frothy urine, headache, visual issues, RUQ pain, hyperreflexia
Urgent hospital assessment if suspected
-> 1 high or 2 mod RF then 75mg aspirin from 12wk-birth, admit if BP>160/110, treat HTN, delivery is definitive
Comp - eclampsia, IUGR, prem, HELLP, haemorrhage, HF
Anaemia
Measure at booking and 28wk appt
- T1 <110, T2/3 <105, pp <100
-> continue PO ferrous sulphate until 3m after resolution
Normal changes in pregnancy
Increase
CO, HR, SV, tidal volume
Blood volume, WCC, ESR
Fibrinogen and factors
ALP
GFR
Trace glycosuria
Reduced
Diastolic BP in T1/2
PLT
Fibrinolytic activity
Albumin
Reduced fetal movements
Movements by week 24, earlier if prev. children
RF - postural (inc when lying), distraction, placental/ fetal position, alcohol, sedatives, body habitus, fetal size
Inv - handheld doppler to confirm HB
> 28wks -> CTG 20mins vs immediate US if HB not found
If 24wks and still no movement-> refer to fetal medicine
RA and pregnancy
Symptoms get better in pregnancy
-> Stop methotrexate 6m before conception, use sulfasalazine/ hydroxychloroquine, may use low dose steroids, no NSAIDs after 32wks
Refer to obs anaesthetist (risk of atlantoaxial subluxation)
Shoulder dystocia
Inability to deliver body using gentle traction after head already delivered, ant. shoulder impacted on pubic symphysis
RF - macrosomia, DM, prolonged labour, fat mum
-> McRoberts (flexion and abduction of hips), episiotomy
Symphsis fundal height
Top of pubic bone to top of uterus
Should match gestational age (+/- 2cm) after 20wks
Umbilical Cord Prolapse
Umbilical cord descends ahead of the presenting part of the fetus
RF - prem, multiparity, polyhydramnios, twins, abnormal presentation, 50% after artificial rupture of membranes
= abnormal HB, palpable cord
-> push presenting part of fetus back in, minimal handling if cord visible, keep it warm/ moist, go on all fours, tocolytics (v contractions), retrofill bladder, c-section
Comp - cord compression, cord spasm
Rhesus-ve Pregnancy
Sensitising events;
Delivery of Rh+ve baby
Termination
Miscarriage >12 weeks
Ectopic managed surgically
ECV
APH
Amniocentesis/ CVS
Abdominal trauma
-> anti-D Ig <72hrs, Kleinhauer test if >20wks, all babies born to Rh-ve mum should have cord blood taken for FBC, BG, Coombs
Rhesus Disease
= hydrops fetalis (oedematous), jaundice, anaemia, hepatosplenomegaly, HF, kernicterus
-> transfuse, UV phototherapy
Bleeding in 1st Trimester
Causes - miscarriage, ectopic, implantation, ectropion
Positive test + any of; abdo pain, pelvic tenderness or cervical motion tenderness
-> immediate EPAU
Bleeding + no RF for ectopic;
>6wks -> EPAU (TV US)
<6wks -> observe 7-10d then repeat HCG, return if pos, miscarriage if neg
Hyperemesis Gravidarum
RF - ^hCG (multiple, trophoblastic), 8-12wks, nulliparous, smoking reduces the risk
= triad of 5% pre-pregnancy weight loss, electrolyte imbalance and dehydration
Inv - Pregnancy-Unique Quantification of Emesis (PUQE) score of severity
-> anti-histamine 1st (cyclizine, chlorpromazine), metoclopramide (no more than 5d) or ondansetron (^cleft in T1) 2nd, 0.9% NaCl + K to rehydrate
When to admit N+V
Cannot keep liquid down
Associated ketonuria or 5% weight loss despite antiemetics
Suspected co-morbidity
When to do continuous CTG during labour
suspected chorioamnionitis or sepsis, or a temperature of 38°C or above
severe hypertension 160/110 mmHg or above
oxytocin use
the presence of significant meconium
fresh vaginal bleeding that develops in labour
