Obstetrics Flashcards
Increased AFP causes
Neural tube defects (meningocele, myelomeningocele and anencephaly)
Abdominal wall defects (omphalocele and gastroschisis)
Multiple pregnancy
Decreased AFP causes
Down’s syndrome
Trisomy 18
Maternal diabetes mellitus
Lifestyle advice to pregnant woman?
DO!!
- Folic acid 400mcg- before conception until 12 weeks-> reduce the risk of neural tube defects.
(higher requirements in certain conditions)
- 10 micrograms of vitamin D per day
- maternity rights and benefits. ask whether they work, usually safe but check for concerns -> The Health and Safety Executive
- beginning or continuing moderate exercise
- N&V- natural remedies (ginger and acupuncture on ‘p6’ point), promethazine (antihistamine) first line
DON’T
- No vitamin A supplementation (intake above 700 micrograms) = teratogenic.
- No drinking
- No smoking - NRT can be used, but not varenicline nor bupropion
- listeriosis - Avoid unpasteurised milk -> ripened soft cheeses (Camembert, Brie, blue-veined cheeses), pate or undercooked meat
- salmonella: avoid raw or partially cooked eggs and meat, especially poultry
- No Airtravel: women > 37 weeks singleton pregnancy , women with multiple pregnancies >32 weeks (VTE risk) (compression stockings if no CI)
Antenatal care timetable
Uncomplicated pregnancy =7 visits, unless 1st pregnancy = 10 visits
8-12wks (ideally <10)
- Booking visit - lifestyle info, BP, urine dip & culture for asymptomatic bacteriuria, BMI
- Booking bloods - FBC, blood group, rhesus & other antibodies, haemoglobinopathies
- Hep B & syphillis (HIV offered)
10 - 13+6
- Early scan to confirm dates
- check for multiple pregnancy
11 - 13+6
- Down’s syndrome screening, nuchal scan
16
- Info on scan & blood results
- If Hb<11 - consider iron
- BP and urine dipstick
18 - 20+6
- Anomaly scan
28 weeks
- Second screen for anaemia and atypical red cell alloantibodies
- If Hb < 10.5 g/dl consider iron
- anti-D prophylaxis to rhesus -ve
34 weeks
- 2nd dose of anti-D prophylaxis
- Info: labour and birth plan
36
- Check presentation - offer external cephalic version if indicated
- info: on breast feeding, vitamin K, ‘baby-blues’
41
- labour plans and possibility of induction
major causes of bleeding during each pregnancy trimester
1st trimester
Spontaneous abortion
Ectopic pregnancy
Hydatidiform mole
2nd trimester
Spontaneous abortion
Hydatidiform mole
Placental abruption
3rd trimester
Bloody show
Placental abruption
Placenta praevia (mother distressed)
Vasa praevia (Foetus distressed)
Mastitis tx
only treat if
- systemically unwell
- nipple fissure
- symptoms do not improve after 12-24 hours of effective milk removal
- culture indicates infection
flucloxacillin for 10-14 days
Breastfeeding or expressing should continue during treatment
CI to breastfeeding , drugs & other
The following drugs should be avoided:
antibiotics: ciprofloxacin, tetracycline, chloramphenicol, sulphonamides
psychiatric drugs: lithium, benzodiazepines
aspirin
carbimazole
amiodarone
sulfonylureas
methotrexate
cytotoxic drugs
galactosaemia
HIV (still feed in developing world)
breech presentation mx
if < 36 weeks: many fetuses will turn spontaneously
if still breech at 36 weeks -external cephalic version (ECV)- offered from 36 weeks in nulliparous women and from 37 weeks in multiparous women
If the baby is still breech then - planned caesarean section or vaginal delivery
absolute contraindications to ECV
where caesarean delivery is required
antepartum haemorrhage within the last 7 days
abnormal cardiotocography
major uterine anomaly
ruptured membranes
multiple pregnancy
Caesarean sections categories
Cat 1 - immediate threat to the life of the mother or baby, w/in 30 minutes
(suspected uterine rupture, major placental abruption, cord prolapse, fetal hypoxia or persistent fetal bradycardia)
Category 2 - maternal or fetal compromise which is not immediately life-threatening, 75 minutes
Cat 3 - delivery is required, but mother and baby are stable
cat 4 - elective
‘pre-terminal’ CTG features?
indicators for Emergency Caesarean section
terminal bradycardia- baseline fetal heart rate drops to below 100 beats per minute for more than 10 minutes
terminal decelerations- heart rate drops and does not recover for more than 3 minutes
Other changes (late decelerations, reduced variability, fetal tachycardia or bradycardia) are usually investigated with fetal scalp blood sampling and an ABG, looking for acidosis
Management of chickenpox exposure in pregnancy,
post-exposure prophylaxis (PEP) & Management of chickenpox in pregnancy
PEP
any doubt about previously having chickenpox -> check varicella antibodies
1st line - oral aciclovir (or valaciclovir) is now the first choice at any stage - day 7 to day 14 after exposure
Chickenpox evelops
- oral aciclovir should be given if the pregnant women is ≥ 20 weeks & presents within 24 hours of onset of the rash
- if the woman is < 20 weeks the aciclovir should be ‘considered with caution’
Down’s syndrome pregnancy screening
combined test is standard
- between 11 - 13+6 weeks
- ↑ HCG, ↓ PAPP-A, thickened nuchal translucency
(pregnancy-associated plasma protein A = PAPP-A)
(trisomy 18 (Edward syndrome) and 13 (Patau syndrome) give similar results but the hCG tends to lower)
if women book later in pregnancy the quadruple test should be offered between 15 - 20 weeks
Results:
‘lower chance’: 1 in 150 chance or more e.g. 1 in 300
‘higher chance’: 1 in 150 chance or less e.g. 1 in 100
quadruple test results?
between 15 - 20 weeks, quadruple test: alpha-fetoprotein, unconjugated oestriol, human chorionic gonadotrophin and inhibin A
Down’s: low AFP & unconj estriol, high HCG & inhibin A (everything low, except HI)
Edward: low everything, normal inhibin
Neural tube: high AFP, low everything else
Results
‘lower chance’: 1 in 150 chance or more e.g. 1 in 300
‘higher chance’: 1 in 150 chance or less e.g. 1 in 100
What should be monitored during magnesium sulphate tx?
urine output, reflexes, respiratory rate and oxygen saturations
respiratory depression can occur: calcium gluconate is the first-line treatment for magnesium sulphate induced respiratory depression
(sed to both prevent seizures in patients with severe pre-eclampsia and treat seizures once they develop - continue for 24 hours after last seizure or delivery)
Causes of folic acid deficiency:
phenytoin
methotrexate
pregnancy
alcohol excess
Prevention of neural tube defects (NTD) during pregnancy:
400mcg of folic acid before conception until the 12th week of pregnancy
5mg for:
- either partner has a NTD, previous pregnancy w NTD, a family history of a NTD
- taking antiepileptic drugs or has coeliac disease, diabetes, or thalassaemia trait.
- woman is obese ( [BMI] >=30 kg/m2 ).
gestational diabetes dx
screening: oral glucose tolerance test (OGTT) - if pmh of GDM: asap after booking & 24-28 weeks. any of the other risk factors: OGTT at 24-28 weeks
Diagnostic:
fasting glucose is >= 5.6 mmol/L
2-hour glucose is >= 7.8 mmol/L
Management of gestational diabetes
if the fasting plasma glucose level is < 7 mmol/l a trial of diet and exercise should be offered
- targets not met in 1-2 weeks-> metformin
- still not met-> insulin (short acting, not long acting)
If fasting glucose level is >= 7 mmol/l OR 6-6.9 & evidence of complications (macrosomia or hydramnios) - insulin should be started
Pre existing DM: stop oral hypoglycaemic agents except metformin, start insulin, folic acid 5 mg/day
Targets:
fasting: 5.3 - mmol/l
Group B step mx
No screening
women who’ve had GBS detected in a previous pregnancy / previous baby with early- or late-onset GBS disease / preterm labour / women with a pyrexia during labour (>38ºC)
-> offered intrapartum antibiotic prophylaxis (IAP) - benzylpenicillin
Pregnancy HTN mx
Hypertension in pregnancy: 140/90 0r 30/15 above booking reading
Pre-existing HTN - high BP before 20 wks
- stop ACEi before pregnancy, start labatalol
Gestational - after 20 wks, no proteinuria nor oedema
- oral labetalol, nifedipine/ hydralazine if asthmatic
Pre-eclampsia is above w proteinuria
- Women who are at high risk of developing pre-eclampsia should take aspirin 75mg od from 12 weeks until the birth of the baby.
Bishop score
help assess whether induction of labour will be required
score of < 5 - labour is unlikely to start without induction
>= 8 - there is a high chance of spontaneous labour, or response to interventions made to induce labour
cervical position
0- posterior
1- intermediate
2 - anterior
cervical consistency
0 - firm
1 - intermediate
2 - soft
cervical effacement
0 - 0-30%
1 - 40-50%
2 - 60-70%
3 - 80%
cervical dilation
0 - <1cm
1 - 1-2cm
2 - 2-4cm
3 - >5cm
fetal station
0- -3
1 - -2
2 - -1,0
3 - +1,+2
Induction of labour
membrane sweep (adjunct to induction of labour rather than an actual method of induction)
vaginal prostaglandin E2 (PGE2) - dinoprostone
oral prostaglandin E1 - misoprostol
maternal oxytocin infusion
amniotomy (‘breaking of waters’)
cervical ripening balloon
if the Bishop score is ≤ 6 - vaginal prostaglandins or oral misoprostol
If Bishop score is > 6 - amniotomy and an intravenous oxytocin infusion
Intrahepatic cholestasis of pregnancy
mx
induction of labour at 37-38 weeks
ursodeoxycholic acid
vitamin K supplementation
Labor stages
stage 1: from the onset of true labour to when the cervix is fully dilated (10-16 hours in primigravida)
- latent phase = 0-3 cm dilation, normally takes 6 hours
- active phase = 3-10 cm dilation, normally 1cm/hr
- less painful than 1st, lasts 1hr if longer consider Ventouse extraction, forceps delivery or caesarean section
stage 2: from full dilation to delivery of the fetus
- ‘passive second stage’ refers to the 2nd stage but in the absence of pushing (normal)
- active second stage’ refers to the active process of maternal pushing
stage 3: from delivery of fetus to when the placenta and membranes have been completely delivered
Head enters pelvis in occipito-lateral position. The head normally delivers in an occipito-anterior position.
Placenta praevia ix
digital vaginal examination should not be performed before USS as it may provoke a severe haemorrhage
transvaginal ultrasound
Placenta praevia mx
If low-lying placenta identified at the 20-week scan:
- rescan at 32 weeks -> if still present, scan every 2 weeks
- no need to limit activity or intercourse unless they bleed
final ultrasound at 36-37 weeks -elective caesarean section for grades III/IV between 37-38 weeks
if grade I then a trial of vaginal delivery may be offered
if a woman with known placenta praevia goes into labour- emergency c section
placental abruption mx
Fetus alive and < 36 weeks
- fetal distress - immediate caesarean
- none - observe closely, steroids, no tocolysis
Fetus alive and > 36 weeks
- fetal distress: immediate caesarean
- no fetal distress: deliver vaginally
post partum haemorrhage definition and causes
> 500ml after vaginal delivery
Primary (w/in 24hrs)
- Tone - uterine atony
- trauma - perineal teal
- tissue - retained placenta
- thrombin - clotting/ bleeding disorder
Secondary (24hrs - 6wks)
- due to retained placental tissue or endometriosis
PPH mx
ABC
- lie woman flat
- catheterise - prevent bladder distension and monitor U/O
1st: mechanical - palpate the uterine fundus and rub it to stimulate contractions (‘rubbing up the fundus’)
2nd: IV Oxytocin (Syntocin) THEN Ergometrine unless the patient has hypertension
3rd: IM Carboprost (unless asthma)
5th: sublingual or Rectal Misoprostol
6th: intrauterine Balloon Tamponade (esp for uterine atony)
7th: B-Lynch suture, ligation of uterine/iliac arteries
8th: life-saving emergency hysterectomy
Postnatal depression mx
(start within a month and typically peaks at 3 months)
Cognitive behavioural therapy
SSRI: sertraline/ paroxetine
(baby blues - 3-7 days following birth)
Pre-eclampsia definition
new-onset blood pressure ≥ 140/90 mmHg after 20 weeks of pregnancy, AND 1 or more of the following:
Proteinuria
other organ involvement e.g. renal insufficiency (creatinine ≥ 90 umol/L), liver, neurological, haematological, uteroplacental dysfunction
Prevention of hypertensive disease in pregnancy
women with the following should take aspirin 75-150mg daily from 12 weeks gestation until the birth
≥ 1 high risk factors
≥ 2 moderate factors
High
- CKD
- autoimmune disease: SLE, antiphopholipid
- DM
- chronic HTN
- HTN in previous pregnancy
Moderate
- primip
- >40yrs
- pregnancy interval of > 10 yrs
- BMI >35
- FH pre eclampsia
- multiple pregnancy
Pre eclampsia mx
emergency secondary care assessment for any woman in whom pre-eclampsia is suspected
BP ≥ 160/110 mmHg - admitted and observed
oral labetalol is now first-line
- or Nifedipine (e.g. if asthmatic) and hydralazine
delivery of the baby is definitive management
anaemia tx
oral ferrous sulfate or ferrous fumarate
- continued for 3 months after iron deficiency is corrected
cut-offs to determine whether a woman should receive oral iron therapy:
1st trimester - < 110 g/L
2nd/3rd - < 105 g/L
Postpartum - < 100 g/L
Risk of prematurity
increased mortality depends on the gestation
respiratory distress syndrome
intraventricular haemorrhage
necrotizing enterocolitis
chronic lung disease, hypothermia, feeding problems, infection, jaundice
retinopathy of prematurity
hearing problems
Preterm prelabour rupture of the membranes ix?
a sterile speculum examination should be performed (to look for pooling of amniotic fluid in the posterior vaginal vault)
- If not seen -> testing the fluid for placental alpha microglobulin-1 protein (PAMG-1) (e.g. AmniSure®) or insulin-like growth factor binding protein‑1
digital examination should be avoided due to the risk of infection
Mx Preterm prelabour rupture of the membranes
oral erythromycin should be given for 10 days
antenatal corticosteroids should be administered to reduce the risk of respiratory distress syndrome
delivery should be considered at 34 weeks of gestation
Reduced fetal movements mx
- handheld Doppler to confirm fetal heartbeat
- no HB-> immediate ultrasound
- HB -> CTG
If fetal movements have not yet been felt by 24 weeks, onward referral should be made to a maternal fetal medicine unit.
Shoulder dystocia mx
Senior help should be called
McRoberts’ manoeuvre
- flexion and abduction of the maternal hips, bringing the mother’s thighs towards her abdomen
- rotation increases the relative anterior-posterior angle of the pelvis and often facilitates a successful delivery.
Umbilical cord prolapse mx
- presenting part of the fetus may be pushed back into the uterus to avoid compression
- minimal handling and it should be kept warm and moist to avoid vasospasm
- patient is asked to go on ‘all fours’
- tocolytics may be used to reduce uterine contractions
- retrofilling the bladder with 500-700ml of saline
