AEGiS-15IAC: The continuing conundrum of mode of delivery in HIV-infected women in the HAART era.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

The continuing conundrum of mode of delivery in HIV-infected women in the HAART era.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. ThOrC1419)

Thorne C, Newell ML; Institute of Child Health, London, United Kingdom

BACKGROUND: The elective caesarean section (CS) rate in the European Collaborative Study (ECS) rose to 30% in the mid-1990s with the finding of the protective effect of elective CS in reducing mother-to-child transmission (MTCT). The approximate halving of MTCT risk with elective CS was confirmed in a clinical trial in the late 1990s. However, in the HAART era, the need for elective CS has been questioned. With the current low MTCT rates, to date no study has been able to examine the effectiveness of elective CS in women with undetectable viral loads.

METHODS: In the ECS, HIV-infected pregnant women and their infants are followed-up prospectively. Data from 4377 mother-child pairs enrolled by December 2003 were analysed.

RESULTS: The elective CS rate fell from 71% in 1999 to 62% in 2002. Although some of this decline was associated with an increasing emergency CS rate due to prematurity, there was a significant increase in the vaginal delivery rate from 13% in 2001 to 21% in 2002. Among 678 women with antenatal HAART, the MTCT rates by mode of delivery were 1.9% (2/107, 95% CI 0.23-6.59%), 2.4% (3/123, 95% CI 0.51-6.96%) and 1.1% (5/448, 95% CI 0.36-2.59%) for vaginal, emergency CS and elective CS respectively. In multivariable logistic regression (n=1741), adjusting for antenatal ART, maternal CD4 count, gender and time period, elective CS was associated with a halving of MTCT risk (AOR 0.51, 95% CI 0.31-0.82, p=0.006). In a sub-analysis of 481 women (51% on HAART) with undetectable HIV RNA levels in pregnancy (49% with<50 copies/ml and a further 31% with<200 copies/ml), elective CS could be seen to significantly reduce MTCT risk (OR 0.11, 95% CI 0.03-0.37) (p=0.0004).

CONCLUSIONS: Although very low MTCT rates are now achievable, use of elective CS even in women with undetectable viral load continues to further reduce the MTCT risk; however, in absolute terms, many elective CS deliveries would need to be performed to prevent one vertical infection.

Keywords: AEGIS, Antiretroviral Therapy, Highly Active, HIV, Acquired Immunodeficiency Syndrome, HIV Seropositivity, Delivery, Obstetric, CD4 Lymphocyte Count, HIV Infections, Viral Load, Pregnancy Complications, Infectious, Anti-HIV Agents, Cesarean Section, HIV-1, Infection, Puerperal Infection, Humans, Female, Pregnancy, Child, Infant, surgery

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ThOrC1419