Infections in Pregnancy

Question 1

VARICELLA ZOSTER VIRUS

1. Maternal risks
2. Fetal varicella syndrome(FVS)
3. Shingles in infancy
4. Severe neonatal varicella
5. Management

Answer 1

1. 5x greater risk of pneumonitis
2. • Risk around 1% if maternal varicella exposure <20w
     - Very small risk if 20-28w, and none >28w
     - Features: skin scarring, microphthalmia, limb hypoplasia, microcephaly, learning disablities
3. 1-2% risk if maternal exposure in 2nd or 3rd trimester
4. If mom develops rash btw 5d before and 2d after birth
   - fatal in 20% cases
5. • Check for varicella antibodies
     - Give varizella zoster immunoglobulin asap if not immune to varicella. Effective up to 10d post-exposure
     - oral aciclovir if pregnant woman with chickenpox presents within 24h of onset of rash

Question 2

HIV

1. Aim
2. Screening
3. Management

Answer 2

1. Reduce vertical transmission to fetus(from 25-30% to 2%)
2. Offered to all pregnant women
3. a) Maternal antiretroviral therapy
   - offered to all if previously taken
   b) Mode of delivery
   - Attempt vaginal delivery if viral load <50 copies/mL at 36w
   - C-section if otherwise. Start zidovudine infusion 4h before beginning C-section
   c) Neonatal antiretroviral therapy
   - Oral zidovudine if viral load <50 copies/mL. Otherwise triple ART.
   - Therapy for 4-6w
   d) Infant feeding
   - NICE: all women advised not to breastfeed

Question 3

Group B-Streptococcus:

1. Risk factors
2. Management

Answer 3

1. Prematurity, prolonged rupture of membranes, previous sibling GBS infection, maternal pyrexia(secondary to chorioamnionitis)
2. -If detected during antenatal period, IV antibiotics during labour. Reduces early-onset GBS disease in neonate

Question 4

UTI Management:

Answer 4

1. Urine culture performed routinely at first antenatal visit
   - If positive, second urine culture to confirm presence of bacteriuria
   - Treat asymptomatic bacteriuria with an antibiotic(SIGN) for 7d
   - repeat urine culture after course of treatment
2. Symptomatic relief with paracetamol
3. Choice of antibiotic(in order of preference) based on NICE 2015:
   a) Nitrofurantoin 50 mg QDS/100 mg BD for 7d
   b) Trimethoprim 200 mg BD for 7d(off-label use). Also give folic acid 5mg daily if in first trimester. Trimethoprim CI if folate deficient/taking folate antagonist/treated with trimethoprim in past year
   c) Cefalexin 500 mg BD/250 mg QDS for 7d