Pregnancy a risk factor for poor antiretroviral treatment outcomes in South African adolescents

Adolescent girls starting antiretroviral treatment (ART) have high incidence of pregnancy and higher probability of poor outcomes in South Africa, according to data presented at the 2014 Southern African Clinicians Society Conference.

On the whole, adolescents started ART with advanced HIV but pregnant adolescent girls started earlier – likely due to testing at maternal facilities. Pregnant adolescents were more likely to be lost to follow-up, have poor viral suppression and viral failure after starting ART.

Geoffrey Fatti from Kheth’Implio – an organisation that supports the South African Department of Health in HIV service delivery – showed findings from an evaluation of gender differences in baseline characteristics of adolescents (aged 9-19 years) starting ART at routine facilities.

The investigators used data from 82 public facilities in four provinces supported by the organisation. ART-naive adolescents starting ART between 2004-2011 were included in the analysis. Of 3175 adolescents, 67% (n=2127) were girls with a pregnancy rate of 10.7% (n=227).

Multivariate analysis revealed that the age of ART initiation was younger among boys in the cohort, and non-pregnant girls started earlier than those who were pregnant, respectively: 11.6, 15.5 and 18.9 years, p=0.0001. Pregnancy incidence increased over the study period to 25.3% in 2011.

The median baseline CD4 count at initiation was significantly higher among pregnant girls: 147, 143 and 205 cells/mm3 for boys, non-pregnant and pregnant girls respectively, p=0.0001.

At 36 months from starting ART, cumulative incidence of mortality was similar among the different groups, pregnant girls aSHR 1.03 (95% CI 0.23-4.51), p=0.96. But loss to follow up was significantly higher in pregnant girls compared to boys, aSHR 1.94 (95% CI 1.03-3.65), p=0.04 (non-pregnant girls aSHR 1.29[95% CI 0.91-1.86], p=0.2).

At 24 months a smaller proportion of pregnant girls achieved viral suppression aSHR 0.58 (95% CI 0.39-0.86), p=0.006 (non-pregnant girls aSHR 0.92 [95% CI 0.57-1.48], p=0.73). By 36 months the cumulative probability of viral failure was greater among pregnant girls, aSHR 4.85 (95% CI 1.78-13.1), p=0.002 (non-pregnant girls aSHR 1.12 [95% CI 0.67-1.88], p=0.65).

Dr Fatti stressed that programmes targeted at reducing adolescent pregnancy and increased adherence support for pregnant adolescents are essential. Both to improve outcomes of adolescents on ART, as well as potentially reduce vertical transmission of HIV.