Human immunodeficiency virus (HIV) - perinatal

The mode of birth and use of intrapartum zidovudine is determined by the maternal viral load at 36 weeks' gestation. The intrapartum care plan should be made in consultation with an infectious disease specialist and obstetrician.

Mode of birth

• Planned caesarean section at 38-39 weeks is often recommended for women with a detectable viral load (≥ 50 copies/mL) at 36 weeks' gestation.
• Vaginal birth is possible for women who take HAART throughout the pregnancy and who have an undetectable viral load.

Other considerations

• Steroid use: there are no known contraindications to the use of short-term steroids to promote fetal lung maturity in women with HIV.
• Anaesthesia: there are no known contraindications to an HIV positive woman having either a general or epidural anaesthetic.
• Avoid early artificial rupture of membranes (ARM), unless a normal birth is expected within four hours.
• Oxytocin can be given for induction or augmentation of labour with intact membranes.
• Assess fetal wellbeing using non-invasive methods; avoid use of fetal scalp electrodes and fetal blood sampling.
• Instrumental deliveries should be avoided unless there is a clear obstetric indication. If required, forceps is preferred to ventouse.
• Prior to any procedures on the neonate that will disrupt skin or mucous membrane integrity, ensure the area is thoroughly cleaned.
• Ensure that standard precautions are used when handling and cleaning up blood and body fluid spillage.

Intrapartum AZT (Zidovudine - Retrovir®)

• Prescription of ART should always be discussed with an infectious diseases physician.
• Zidovudine is an anti-retroviral agent used to reduce the risk of perinatal transmission of HIV. This drug crosses the placenta thus providing fetal prophylaxis.
• Indications for intrapartum zidovudine:
  • Viral load > 50 copies/mL at 36 weeks
• Late presenter, not on HAART (in these patients additional antiretroviral drugs may be required)
• Dose: 2 mg/kg for the first hour, followed by infusion at a rate of 1 mg/kg/hour.
• Preparation of infusion:
  • Each 20 mL vial (for injection) contains 200 mg zidovudine (available via Special Access Scheme (SAS) category A.).
  • First withdraw 40 mL of sodium chloride 0.9 per cent from the 100 mL normal saline bag.
  • Add 400 mg (40 mL zidovudine solution) to this 100 mL sodium chloride 0.9 per cent bag.
  • This solution gives a total dose = 400 mg in 100 mL (4 mg/mL).
• Timing of administration:
  • For planned Caesarean: start zidovudine four hours prior
  • If spontaneous labour occurs prior to Caesarian: start zidovudine during the preparation (however, the Caesarean section should not be delayed to complete the IV course of zidovudine)
  • Cease zidovudine once the neonates umbilical cord has been clamped.

Postnatal care management at birth

Minimise the risk of mixing maternal and infant blood by:

• wiping secretions from the infant’s eyes and head after birth
• using suction gently if it is required – to avoid damage to mucous membrane
• clamping the cord as soon as possible, milking between clamps in direction away from the infant
• placing  a sponge over the cord before cutting to prevent blood spurting
• drying the infant prior to any procedure (for example, vitamin K injection)
• conducting a clinical examination including growth and neurodevelopmental assessment.

Neonatal management should always be in consultation with an infectious disease consultant.

Antiretroviral therapy

All neonates will require zidovudine therapy within six hours after birth.

Dosage

Oral zidovudine (10 mg/mL syrup):

• GA ≥ 35 weeks: 4 mg/kg/dose orally 12-hourly for four weeks
• GA 30-34 weeks: 2 mg/kg/dose orally 12-hourly for two weeks, then 2 mg/kg/dose eight-hourly for two weeks
• GA <30 weeks: 2 mg/kg/dose 12-hourly for four weeks

IV zidovudine (if unable to tolerate oral zidovudine)

• Term: 1.5 mg/kg/dose IV six-hourly
• Preterm: 1.5 mg/kg/dose IV 12-hourly

Side effects

• Nausea, vomiting, headache, fever
• Anaemia, neutropenia, leukopenia
• Abnormal liver function tests – elevated bilirubin, transaminitis
• Monitor FBE, LFTs at two and six weeks of age

Contraindications

• Avoid in infants with low neutrophil counts (< 0.75 x 109/L) or low haemoglobin (< 75 g/L). Discuss with an infectious diseases physician for an alternative option.

Neonates with a high risk of MTCT (detectable or unknown viral load; maternal viral load not measured; late presentation) require additional ART drugs. This should be discussed with an infectious diseases physician.

Feeding

• Breastfeeding is NOT recommended in women with HIV due to the risk of viral transmission through breast milk.
• Formula feeds are preferred.
• Skin-to-skin contact between mother and baby should be encouraged.

Investigations

A suggested schedule for HIV testing of the baby includes:

• HIV proviral DNA or HIV RNA PCR testing at:
  • one week (prior to discharge)
  • six weeks
  • three months.

  Note: Take 2 mL of blood via a peripheral vein for HIV PCR testing.

• HIV antibody (Ab) testing at 18 months. Note: HIV antibodies pass through the placenta to the fetus and can be detected in the infant for up to 12-18 months. HIV Ab testing should be done at 18 months of age to document clearance of HIV Ab.  

Pneumocystis jirovecii (PJP) prophylaxis

• The decision for PJP prophylaxis should be made with an infectious diseases physician.
• Indications for PJP prophylaxis:
  • PJP prophylaxis is not recommended for ‘low-risk’ infants for whom all preventive interventions have been utilised and with two negative HIV PCR results.
  • Consider in high-risk infants (maternal viral load > 1,000 copies/mL at 36 weeks despite HAART or unknown viral load).
• This should be commenced at six weeks and continued until two HIV DNA PCR tests are negative.

Follow-up

• Routine childhood immunisations should be given to all infants born to HIV-positive infants.
• Live vaccines (MMR, varicella and BCG) should be discussed with an infectious diseases physician.
• All babies born to HIV positive women should be followed into adulthood by a paediatrician.

Clinical

• ASID perinatal guidelines
• CDC HIV/AIDS
• USA Perinatal HIV Guidelines (Last accessed November 2013)

Consumer

• Better Health Channel - HIV and women - having children

References

1. Havens PL, Mofenson LM. Evaluation and management of the infant exposed to HIV-1 in the United States. Pediatrics. Jan 2009;123(1):175-187.
2. Ferguson W, Goode M, Walsh A, Gavin P, Butler K. Evaluation of 4 weeks' neonatal antiretroviral prophylaxis as a component of a prevention of mother-to-child transmission program in a resource-rich setting. Pediatr Infect Dis J. May 2011;30(5):408-412.