obstetrics: ANC, LW and PP Flashcards
threshold for using HC for EDD
CRL >84mm
Nuchal translucency threshold
>6mm
obesity increases risks of which maternal complications
PPHx2 GDM x3.6 VTE x9 Hypertensive disorders SB x2 Fetal macrosomia C/S Death (MBRRACE2015 - 30% of women who died were obese)
Class I obesity
BMI 30-34.9
Class II obesity
BMI 35-39.9
Class III obesity
BMI >40 (increases M/M by 60%)
how long to wait after bariatric surgery prior to conception
12-18 months
% pregnancies affected by PIH
4-7%
% of pregnancies affected by PET
2-8%
incidence eclampsia
27/10 000 (approx 1/370)
mortality eclampsia
1/50
stillbirth eclampsia
22/1000 (approx 1/45)
high risk factors for aspirin
- prev PET/PIH - CKD - Autoimmune conditions - DM - Chronic HTN
Moderate risk factors for aspirin (2+)
- primip - age >40 - pregnancy interval ?10 - BMI >35 - FHx - multiple pregnancy
indications for delivery <37/40 in PET
- uncontrolled BP x3 medications - Sat <90% - Deteriorating bloods - Neuro features - Abruption - abnormal doppler or CTG
antidote to MgSO4
10ml 10% calcium gluconate
HELLP incidence
15-20% of PET cases
HELLP associated with DIC in ___%
21% up to 50% will require blood products
HELLP diagnostic criteria
MAH LDH >600 Haptoglobin <25 PLT <100 AST >70
SGA: UA Doppler Normal - When to repeat USS?
Fortnightly: AC & LV; EFW UA Doppler (MCA after 32 weeks)
SGA: UA Doppler Normal - When to offer delivery?
at 37/40 with involvement of senior clinician
SGA: UA Doppler Normal - When to recommend delivery?
by 37/40 if MCA Doppler PI <5th centile
SGA: UA Doppler normal - when to consider delivery?
>34/40 if static growth over 3 weeks
SGA: PI or RI >2SDs, EDV present - when to repeat USS?
Weekly AC & LV; EFW Twice weekly UA Doppler
SGA: PI or RI >2SDs, EDV present - when to recommend delivery?
by 37/40
SGA: PI or RI >2SDs, EDV present - when to consider delivery?
>34/40 if static growth over 3 weeks
SGA: AREDV - when to repeat USS?
weekly AC & LV; EFW Daily UA Doppler, DV Doppler +/- cCTG if DV doppler unavailable
SGA: AREDV - when to recommend delivery?
<32/40 after steroids if abnormal DV doppler and/or cCTG STV <3ms
SGA: AREDV - fetal prerequisites for early delivery
>24/40 and EFW >500g
SGA: AREDV - when to consider delivery?
30-32/40 even when DV doppler is normal
definition of abnormal uterine artery doppler
PI >95th centile and/or notching
if severe SGA identified at 18-20 week scan :
offer referral for a detailed fetal anatomical survey and uterine artery doppler by a fetal maternal specialist;
SGA: karyotyping should be offered for
severely SGA foetuses (<3 centile) with structural abnormalities; and those detected <23/40 *triploidy most common*
timing of birth for DCDA twins
37+0 to 37+6
timing of birth for MCDA twins
36+0 to 36+6
timing of birth for MCMA twins (uncomplicated)
32+0 to 33+6
timing of birth for triplets (uncomplicated)
35 to 35+6
multiple pregnancy: if decline birth at recommended timing:
- ANC wkly with obstetrician - AFI + doppler weekly - Growth USS 2 wkly
MC twins - TTTS - timing of birth
34-36+6 if no other indications
MC twins - type 1 SGR - timing of birth
34-36/40
MC twins - Type 2-3 SGR - timing of birth
By 32/40 unless growth velocity significantly abnormal or worsening dopplers
MC Twins - after twin 1 demise - incidence of 2nd IUFD
15%
MC Twins - after twin 1 demise - incidence of neurological abnormality in 2nd twin
26%
GBS: if benpen mild allergy, what alternative?
cefuroxime 1.5g then 750mg q8h
GBS: if benpen severe allergy, what alternative?
vancomycin 1g q12h
what % of women with GBS+ on swab 35-57/40 will be negative at delivery?
17-25%
what % of women with GBS- swab at 35-37/40 will be positive at delivery?
5-7%
GBS PROM at term - risk of serious infection
1%
fetal circulating blood volume
80-100ml/kg
incidence APH
3-5% of pregnancies
blood loss 1000 -1500 associated with what changes in obs
tachycardia, tachypnea, slight recordable fall in SBP
blood loss >1500ml associated with what changes in obs
SBP <80 worsening tachycardia & tachypnea altered mental state
timing of delivery for uncomplicated placenta previa
36-37/40
timing of delivery for placenta previa with history of PVB
34-36+6/40
timing of delivery for placenta accreta
35-36+6/40 (recommend elective admission from 34/40)
timing of delivery for vasa previa if confirmed prior to labour
34-36/40
inducing labour for VBAC associated with ____x risk of C/S
1.5x
inducing labour for VBAC associated with ____x risk of uterine rupture
2-3x
breech complicates ___% term deliveries
3-4%
spontaneous version of breech in nulliparous women after 36/40
8%
unsuccessful ECV: what proportion will spontaneously turn to ceph
3-7%
successful ECV: what proportion will turn back to breech
3%
recurrence of breech next pregnancy
9.9%
proportion of babies in breech position at 28/40
20%
vulval and vulvovaginal hematomas arise from damage to ____
branches of pudendal artery
paravaginal hematomas arise from damage to _____
uterine artery
supralevator/supravaginal hematomas arise from damage to _____
uterine artery in broad ligament
OASIS incidence overall
2.9%
OASIS incidence primip
6.1%
OASIS incidence multip
1.7%
OASIS incidence forceps with epis
6%
OASIS incidence in shoulder dystocia
3.8%
OASIS incidence forceps without epis
22%
OASIS repair anorectal mucosa
continuous or interrupted 3-0 polyglactin (modern braided)
OASIS repair IAS
interrupted to mattress 3-0 PDS or 2-0 polyglactin
OASIS repair EAS
overlapping or end-to-end 3-0 PDS or 2-0 polyglactin
OASIS risk of recurrence
5-7%
OASIS worsening of symptoms after 2nd NVD
17%
shoulder dystocia recurrence
1-25% (10x increase)
shoulder dystocia in DM
2-4x increased risk
shoulder dystocia risk of BPI
2.3-16%
shoulder dystocia humeral fractures with delivery of posterior arm
2-12%
minimal fetal fraction for cffDNA
4%
failed cell-free DNA tests
1-5% higher failure rates in pregnancies with Edwards and Pataus. on repeat sampling, 60% obtain results
main determinants of low fetal fraction cffDNA
maternal obesity small placental mass
Cervical length <25mm - risk of PTL
25% under 28 weeks
Cervical length <20mm - risk of PTL
42% under 32 weeks 62% under 34 weeks
most likely surgical complication in repeat sections
blood transfusion
PROM: risk of infection
1% compared to 0.5% for women with intact membranes
PROM: what % women go into labour within 24h
60%
PROM: until IOL started or if expectant management beyond 24h
- record temp every 4h during day - do not do CRP or LVS - avoid sex - assess fetal movement and heart rate at initial contact and every 24h
PROM: if labour not started 24h later
IOL should stay in hospital for at least 12h after birth
average duration of first stage
primip: 8-18h multip: 5-12h
delay in second stage: primip
suspect after 1h active Diagnose after 2h should have birth within 3h of active
delay in second stage: multip
suspect after 30 minutes active diagnose after 1h active should have birth within 2h of active
able for episiotomy
45-60 degrees right mediolateral
delay in second stage: how often should obstetric review occur
every 15-30 minutes after initial assessment
prolonged 3rd stage
30 minutes active, or 60 minutes physiological
active management of 3rd stage “care package”
uterotonic drug deferred clamping CCT
third stage: N/V in active vs. physiological
100/1000 vs 50/1000
third stage: PPH>1L in active vs physiological
13/1000 vs 29/1000
third stage: need for blood transfusion active vs. physiological
14/1000 vs 40/1000
active management choice of drug for low risk care
syntocinon 10u IM
active management for c/s
syntocinon 5u IV
active management for NVD - absence of hypertension but increased risk of minor PPH
syntometrine
mec obs
1h, 2h then 2h until 12h
PROM neonatal obs
1h, 2h, 6h, 12h
