Stillbirth in Women Living With HIV Delivering in the United Kingdom and Ireland: 2007-2015.

Background: Women living with HIV have a higher risk of adverse birth outcomes, but questions remain regarding their specific risk factors for stillbirth and the extent to which maternal HIV is associated with stillbirth.

Methods: Using data on pregnant women with HIV reported within population-based surveillance in the United Kingdom/Ireland, we described stillbirth rates in 2007-2015 stratified by type of antiretroviral therapy (ART) and evaluated risk factors using Poisson regression. General population stillbirth rates by maternal world region of origin were derived from national annual birth statistics, and compared with rates in women with HIV, using standardized stillbirth ratios with the general population as the reference.

Results: Between 2007 and 2015, there were 10,434 singleton deliveries in 8090 women with HIV; 75% of pregnancies were in women of African origin; and 49% were conceived on ART. The stillbirth rate was 8.5 (95% confidence interval: 6.9 to 10.5) per 1000 births. Risk factors for stillbirth included pre-eclampsia, diabetes, Asian maternal origin (versus United Kingdom/Ireland), CD4 count <350 cells/mm, older maternal age, and primiparity. Conceiving on ART did not increase the risk. The stillbirth rates (per 1000 births) by type of ART were 14.3, 11.7, 8.3, and 6.0, respectively for NVP + XTC/TDF-, LPV/r + 3TC/ZDV-, NVP + XTC/ABC-, and NVP + XTC/ZDV-exposed pregnancies (P value = 0.40). The standardized stillbirth ratio was 129 (95% confidence interval: 101 to 165) in women with HIV compared with the general population.

Conclusion: After adjusting for maternal origin, the stillbirth rate remained higher in women with HIV than the general population. We recommend further studies to understand and prevent this excess.