Planned vaginal delivery appears safe for HIV-positive pregnant women with an undetectable viral load

Planned vaginal delivery appears to be a safe option for HIV-positive pregnant women with an undetectable viral load at the time of delivery, according to a poster presentation at the Eleventh Annual Conference of the British HIV Association in Dublin last week.

Not a single infant born to a mother with an undetectable viral load at the time of delivery was infected with HIV, according to evidence presented by investigators at London’s Chelsea and Westminster Hospital.

“With careful monitoring of women throughout pregnancy and during labour, the risk of HIV transmission with a planned vaginal delivery is very low”, the investigators reported.

Appropriate antiretroviral therapy, the mode of delivery, and the avoidance of breastfeeding can reduce the risks of mother-to-child transmission of HIV to less than 1%. However elective caesarean delivery, like all surgery, involves risks, and can have additional complications for women who may wish to have a subsequent pregnancy.

Because of this, women who were expected to have a viral load below 50 copies/ml at week 36 of pregnancy were offered the option of a planned vaginal delivery by doctors at the Chelsea and Westminster.

Between 1999 and 2004 a total of 24 HIV-positive women cared for at the hospital delivered 32 infants by vaginal birth. Management of their pregnancy was provided by a team including an HIV physician, an obstetrician, an infectious diseases paediatrician, and a specialist HIV midwife.

In addition to having an undetectable viral load, women offered the option of a vaginal delivery were expected to go into labour in the 41st week of pregnancy, have had no previous uterine surgery or a previous elective caesarean, be free of genital infections, and have no indications that their labour would be prolonged.

None of the 24 women who had vaginal deliveries had been diagnosed with AIDS and all were taking HAART at the time of delivery. Equal numbers were taking NNRTI and protease inhibitor-based therapy. The majority of women had started treatment before their pregnancy, but those not on treatment started treatment between weeks 22 and 24.

The median duration of pregnancy was 39 weeks. At the time of delivery all the women had a viral load below 50 copies/ml and the median CD4 cell count was 344 cells/mm³.

Labour lasted a median of just under five and a half hours, and the median weight of infants was a little under three kilograms. However, due to complications in labour, five emergency caesareans were performed. All the infants received prophylaxis with AZT, although in some instances this was changed according to the mother’s antiretroviral regimen or resistance patterns.

None of the infants was infected with HIV.

Although 75% of mothers delivered their infants at the full-term of pregnancy, a quarter of deliveries were pre-term, and the investigators emphasise that this indicates that it is necessary to start HAART no later than week 22 – 24 of pregnancy to allow time for adequate viral suppression to allow the option of a vaginal delivery.

“We are of the opinion that women with a viral load below 50 copies/ml and no obstetric indications for an elective caesarean should be offered a vaginal delivery if this is their preference”, write the investigators.