Background: Although highly successful in reducing the risk of mother-to-child transmission, the increasing use of HAART in HIV-infected women in pregnancy may be associated with adverse pregnancy outcomes.

Methods: In the European Collaborative Study, HIV-infected pregnant women and their infants are followed up prospectively in 9 European countries. Data from 1998 to 2002 were analyzed from this ongoing study, to describe pregnancy outcomes in the HAART era.

Results: Most pregnant women acquired their infection through heterosexual contact (an increasing number were from sub-Saharan Africa) and 80% were asymptomatic (CDC class A). The mother-to-child transmission rate during this period was 3.04% (95% CI 2.06 - 4.32%), reflecting the fact that 88% (1252/1415) of women took antenatal ART, mostly HAART including a PI; a third of women received ART from before pregnancy. There has been a recent decline in the elective caesarean section rate, used as a PMTCT intervention, from 73% in 1999 to 58% (143/245) in 2002, with a corresponding rise in vaginal deliveries, from 12% in 1999 to 24% (59/245) in 2002. Simultaneous with the increase in HAART use was an increasing rate of prematurity (< 37 weeks). Among women having vaginal or emergency caesarean section deliveries, the prematurity rate increased from 26.8% in 1998 to 31.2% in 2002, compared with 14.0% in 1994 to 1997; in particular there were significant increases in the prevalence of severe prematurity (<34 weeks), rising from 3.3% to 16.0%, and of very low birth weight infants (<1500g), increasing from 0.5% to 6.0% between 1994-1997 and 1998-2002. The crude neonatal mortality rate was 13.4/1000 (19 neonatal deaths/1415 live births) in 1998 to 2002, compared with 6.3/1000 (6/947) in 1994-1997, already higher than in the general population. The median gestational age of the neonates who died was 28 weeks (range, 22 to 37 weeks) and median birthweight was 710 g (range, 500 to 2750 g). Neonatal death was primarily related to prematurity complications (16 cases); twins delivered at 25 weeks had evidence of GBS infection and 1 death due to severe asyphyxia. Twelve (63%) neonates were exposed to antenatal HAART, 2 to dual therapy, 2 to monotherapy and 3 to none.

Conclusions:  Although HAART has substantially reduced rates of mother-to-child transmission in Europe, we present some worrying new findings from this ongoing cohort. These suggest the possibility of unexpected adverse effects associated with HAART and further investigation is needed.

Keywords: pregnancy; HAART; adverse outcomes