There are “missed opportunities” for HIV-positive pregnant women with a suppressed viral load to give birth vaginally, European research published in the Journal of Acquired Immune Deficiency Syndromes shows.
Guidelines in Europe recommend or permit a vaginal delivery when a woman has an undetectable or very low viral load. However, investigators found that over a third of women with viral suppression and no contraindications continue to have a caesarean section.
“Rates of vaginal deliveries were lower than expected,” comment the authors. “Our results suggest that the policy for vaginal delivery among women among women with undetectable or very low VL [viral load] is only slowly becoming established within practice over time.”
An elective caesarean section delivery – a caesarean performed before the onset of labour or the rupture of membranes – was recommended for HIV-positive women in 1999 when it was shown to reduce the risk of mother-to-child transmission of HIV.
The widespread use of combination antiretroviral therapy has reduced the risk of mother-to-child transmission dramatically and rates of below 1% are seen across Europe. The additional benefits of an elective caesarean section are open to question, especially as the procedure can also involve risks.
Over the past decade, guidelines across Europe for the management of HIV infection during pregnancy have been changed and now recommend or permit a vaginal delivery for women taking antiretroviral therapy with an undetectable or low (below 50 copies/ml and, in some circumstances, below 400 copies/ml) viral load.
Investigators wanted to see if these changes to guidelines had impacted on rates of women with a suppressed viral load giving birth vaginally. To answer this question they examined data collected between 2000 and 2010 in two studies (the European Collaborative Study and the Swiss Mother and Child HIV Cohort Study). Data on 3013 deliveries to 2663 women were available for analysis.
Overall, 48% of the women were black, and the median maternal age at delivery was 32 years. Three-quarters of the women were infected with HIV via heterosexual contact, and 16% reported a history of injecting drug use. Most of the women (84%) had no symptoms of HIV disease and the median CD4 cell count was 452 cells/mm3. Only 8% of participants had severe immune suppression (a CD4 cell count below 200 cells/mm3).
Three-quarters of women were aware they had HIV before conceiving and in a quarter of pregnancies the participant conceived while taking antiretroviral drugs.
Only 8% of mothers did not receive any HIV treatment during pregnancy or delivery. The proportion receiving no antenatal therapy decreased after the introduction of new guidelines from 9 to 4%.
Of the 1527 women who initiated treatment during pregnancy, 78% did so during the first or second trimesters.
The proportion of women taking combination HIV treatment who achieved a viral load below 400 copies/ml at the time of delivery increased from 83 to 95% after the new guidelines were in place.
Several factors were associated with a detectable viral load at the time of delivery. These included late diagnosis during pregnancy (p < 0.001), younger age (p = 0.005), history of injecting drug use (p = 0.015), use of dual/monotherapy (p < 0.001) and a CD4 cell count below 500 cells/mm3 (p < 0.001).
The proportion of women giving birth vaginally increased from 17 to 52% after the change in guidelines.
Restricting analysis to the 611 births after guidelines recommended or permitted vaginal delivery showed that 45% of those to women with an undetectable viral load and 57% of those to women with a viral load between 50 and 399 copies/ml were vaginal.
Approximately 21% of deliveries after the guidelines change were via emergency caesarean section. A fifth of emergency caesarean sections involved women with an undetectable viral load.
In the years following the introduction of the guidelines, caesarean section was the mode of delivery for 55% of women with an undetectable viral load. In a third of cases there was a factor indicating the need for this mode of delivery. However, in 35% of cases the woman could have had a vaginal delivery.
Analysis of pregnancy outcomes showed that 21% of deliveries were premature. Median birth weight was 2.9 kg. The overall rate of mother-to-child-transmission was 1.6%. The rate was 1.7% before the new guidelines but fell to 0.6% after their publication.
“Rates of vaginal delivery in HIV-positive pregnant women are increasing for women with suppressed VL,” conclude the authors. “Despite this, there is evidence of missed opportunities for viral suppression and for having a vaginal delivery in women with a suppressed viral load.”
Aebi-Popp K et al. Missed opportunities among HIV-positive women to control viral replication during pregnancy and to have a vaginal delivery. J Acquir Immune Defic Syndr, online edition, doiI: 10.1097/QAI.0b013e3182a334e3, 2013.