PREVENTION OF MOTHER TO CHILD TRANSMISSION

There is a high risk of transmission from mother to child when the infected mother has high viral load, low CD4+ T-cell count and associated chorioamnionitis. With administration of ARV therapy to infected mothers, this risk has reduced. Pregnancy has no clear effect on HIV progression. In developing countries, HIV infection is connected to increased rates of preterm delivery, low birth weight and stillbirth. The probability of perinatal transmission without treatment is 20% to 25%, with ZDV monotherapy is 8% to 11% and with HAART is 1% to 2%. Probability of perinatal transmission is directly related to the viral load at time of delivery. When the viral load is > 1000c/ml ART should be suggested.  Avoid NVP regimen in women with CD4 count > 25 cells/cm (this does not affect the single dose prophylactic NPV).
There is no evidence that pregnancy on its own worsens HIV infection or hastens its progression. CD4+ T-cell counts decline during pregnancy in all women (irrespective of HIV status) due to increased plasma volume. HAART has decreased the rate of MTCT in developing countries to as low as 1%. Simple antiretroviral prophylactic regimens can reduce MTCT by 50% to 70% in the absence of breastfeeding and from 38% to 63% short term efficacy at 6 weeks to 6 months in breastfeeding populations. The risk of HIV transmission with breastfeeding is 10% to 16% and greatest in the first 4 to 6 months. There is a 2-fold and a 50-fold increase in risk with mastitis and breast abscess respectively.
Principles: Get viral load of mother to undetectable level before delivery if possible. Prevent baby from coming in contact with mother’s blood (elective caesarean section preferred; vaginal delivery without episiotomy). Give appropriate HIV prophylaxis to mother and child according to guidelines. Avoid breastfeeding.
Prevention of mother to child transmission guidelines
Preferred ARVS in pregnancy
NRTI:                                          ZDV, 3TC
NNRTI:                                       NVP
PI:                                               NFV, SQV/RTC
Alternatives
NRTI:                                          ddl, d4T, ABC, FT
NNRTI:                                       NONE (EFV should be avoided in the first trimester)
PI:                                               IDV, LPV/r, APV, FPV and ATV.
Prevention of mother to child transmission guidelines for untreated women
Choices for pregnant women presenting in labour and infants:
NVP:             200mg po onset of labour; infant 2mg/kg po at 48-72 hours.
ZDV:              600mg po onset of labour and 300mg q3h until delivery PLUS 3TC 150mg po followed by 150mg po q12h until delivery; infant: ZDV 4mg/kg po q12h PLUS 3TC 2mg/kg po q12h 7 days.
NVP + ZDV:
NVP:              200mg po onset of labour plus ZDV 2mg/kg IV bolus then 1mg/kg/hr IV until delivery.
Infant:           NVP single 2mg/kg po at 48-72 hours PLUS ZDV 2mg/kg po q6h for 6 weeks.
Prevention of mother to child transmission guidelines for treated women
ACTG 076 protocol should be used as part of ART regime in all pregnant women if possible.
Antepartum:      ZDV 300mg bid or 200mg bid po wk 14 until delivery.
Intrapartum:      ZDV IV 2mg/kg over the first hour. The 1mg/kg/hr occur until delivery.
Postpartum:       (infant) ZDV syrup 2mg/kg q6h or (1.5mg/kg q6h IV) x 6 wks.