Antepartum Care Flashcards
Incidence of placenta praevia
1 in 200 pregnancies
Resolution rate of placenta praevia at 32 weeks
90%
Resolution rate of placenta praevia at 36 weeks
50%
Cervical length of less than ________ predicts antepartum haemorrhage and emergency c/s
31mm
Risk factors for placenta praevia
Smoking
ART
Caesarean birth
Timing of steroids for placenta praevia
34+0 to 35+6
Timing of delivery in placenta praevia
34+0 - 36+6 if vaginal bleeding/other risk factors
36+0 - 37+0 if uncomplicated
Risk of bleeding by gestation with placenta praevia
4.7% by 35 weeks
15% by 36 weeks
30% by 37 weeks
59% by 38 weeks
Risk of MOH requiring blood transfusion with placenta praevia c/s
12 x higher
Risk factors for PAS
C/S
Previous uterine surgery
Placenta praevia
IVF
Maternal age
Bicornuate uterus
Adenomyosis
Submucous fibroids
Myotonic dystrophy
Rate of PAS with praevia and 3 or more c/s
50-67%
Proportion of PAS undiagnosed
1/3 to 2/3rds
USS signs of PAS
Abnormal uterus-bladder interface
Abnormal vasculature on colour Doppler
Placental lacunae
Increased vascularity of the placental bed
MRI signs of PAS
Abnormal uterine bulging
Dark intraplacental bands
Heterogenous signal intensity in placenta
Disorganised vasculature of placenta
Disruption of uteroplacental zone
Gestation for delivery with PAS
35+0 to 36+0
Risk of urinary tract injury during PAS surgery
16% of uterus preserved
57% with standard hysterectomy
Risks of conservative management of PAS (placenta in situ)
Infection
Bleeding
Septic shock
Peritonitis
Uterine necrosis
Fistula
Pulmonary oedema
Acute renal failure
VTE
Injury to adjacent organs
Emergency cerclage can be considered up from ______ to _____ gestation
16+0 to 27+6
Risk of preterm birth with cervical length of <25mm and history of PTB
14%
Indications for serial cervical length scans
Previous PTB/2nd trimester loss 16-34 weeks
Previous PPROM <34 weeks
Previous cerclage
Intrauterine adhesions
Known uterine variant
History of trachelectomy
Indication for trans abdominal cerclage
Previous failed vaginal cerclage
Risks of cervical cerclage
Cervical laceration
Bladder injury
Membrane rupture
Fistula formation
Removal under anaesthetic required if performed with bladder mobilisation
Removal of cervical suture should be at
36+1 to 37+0 unless pt undergoing c/s
History indicated cerclage
Singleton, 3 or more preterm births
Singleton, history of second trimester loss
Gestation at which you MUST remove cervical cerclage after PPROM
Less than 23 weeks
More than 34 weeks
Incidence of PPROM
3%
PPROM occurs in what percentage of PTB
30-40%
Median latency after PPROM
7 days
Management of PPROM
Delivery if septic
Erythromycin (penicillin if allergic) 10 days or established labour
Offer steroids between 24+0 to 33+6
Consider steroids 34+0 to 35+6
Benefit of abx in PPROM
Reduce babies born within 48 hours and within 7 days
Reduce risk of chorio
Reduces risk of neonatal infection, surfactant use, oxygen therapy and abnormal cerebral USS
Most helpful marker of chorioamnionitis
CRP (77% specificity)
Tocolysis in PPROM is not recommended because
Associated with lower APGAR scores (<7) and increased need for ventilatory support
Increased risk of chorio below 34 weeks
Timing of Delivery following PPROM
37+0
From 34+0 if GBS pos
MgSO4 for PPROM
Offer when Planned or established labour 24+0 to 29+6
Consider between 30+0 and 33+6
Average time to delivery after PPROM
8-10 days at 24+0 to 28+0
5 days at 31+0
May be sooner if there is oligo
Factors leading to worse outcomes for PPROM
Oligo
Non-cephalic presentation
Occurring <26+0
Consider hospital care
Benefits of antenatal steroids
Reduce NND
Reduce NEC
Reduce RDS
Reduce intraventricular haemorrhage
Reduce risk of infection in first 48 hours of life
Reduces risk of ITU admission/respiratory support
Reduce developmental delay
Optimal Timing of steroids
Greatest benefit with delivery within 48 hours of first dose
Benefit seen within 24 hours of delivery
Benefit for up to 7 days of giving
Dose and type of steroids
Dexamethasone phosphate 12mg 24 hours apart or 4 doses of 6mg given 12 hourly (better risk reduction for IVH)
Betamethasone phosphate/acetate mix - 12mg 24 hours apart
Gestations to give steroids
Offer between 24+0 to 34+6
Consider 35+0 to 36+6
Consider between 22+0 to 23+6
Harms of steroids
Affects maternal glycaemic control for 5 days
Neonatal hypoglycaemia
Reduced birth weight with repeat courses
Neurodevelopmental affects if baby born at term
Stillbirth rate
32 in 10, 000 (white)
72 in 10, 000 (black)
51 in 10, 000 (Asian)
Consider Prophylactic vaginal progesterone when
History of PTB up to 34+0/2nd trimester loss OR cervical length is <25mm on TV USS
Offer either cerclage or vaginal progesterone when
History of PTB/2nd trimester loss AND cervical length <25mm
Gestation to give vaginal progesterone
Start between 16+0 and 24+0
Continue until 34+0