Prevalence and correlates of repeat testing during pregnancy and postpartum in rural Kenya

BACKGROUND

Repeat HIV testing during pregnancy and the postpartum period is crucial for early detection and treatment of incident maternal HIV infection, and to achieve elimination of mother-to-child HIV transmission (MTCT). World Health Organization (WHO) guidelines recommend repeat testing of peripartum HIV negative women but data on implementation are lacking. The objective of this study is to determine the uptake and correlates of repeat HIV testing during pregnancy, delivery, and postpartum.

METHODS

HIV seronegative women seeking care during the 3rd trimester, delivery, or at 6 weeks, 6 months, or 9 months postpartum were enrolled in a cross-sectional study in rural Kenya. Prior HIV testing history was abstracted from maternal child health (MCH) booklets to estimate prevalence of repeat testing at different timepoints. Poisson generalized linear models were used to determine correlates of repeat testing. We externally validated a risk score tool to predict maternal HIV infections using area under the curve (AUC) and Brier score.

RESULTS

Among 1558 women enrolled, the median age was 23 years, 60% of women were married and the median number of times tested for HIV in the most recent pregnancy was 1 (interquartile range [IQR]: 1-2). Prevalence of new HIV infection detected by the study was 0.4% with no difference between pregnant and postpartum women (Odds ratio: 0.8, 95% Confidence Interval [CI]: 0.2-3.7; p=0.8). Prevalence of programmatic repeat HIV testing at 6 weeks (51%) postpartum was significantly higher than in the 3rd trimester (22%), during delivery (5%) and 6 months postpartum (32%) (p= <0.001). In multivariate analysis, women with more lifetime number of sexual partners (Prevalence Ratio [PR]: 0.97 per 1 unit increase, CI: 0.95-0.99; p=.007), with history of sexually transmitted infection (STI) (PR: 1.18, CI: 1.10-1.27; p=<.001) and women who were 21-30 years were less likely than women <21 years (PR: 0.87, CI: 0.81-0.93; p=<.001) to receive ≥1 programmatic repeat tests. External validation of a risk score tool yielded an AUC of 0.82 (95%CI: 0.68-0.93) and Brier score 0.21.

CONCLUSION

Prevalence of repeat testing was higher during the early postpartum period than in late pregnancy. Developing strategies that address barriers and increase antenatal care (ANC) attendance, could improve uptake of repeat testing during pregnancy.