Trends in maternal characteristics and pregnancy outcomes among women living with HIV in England: 2015-2020

Background

The vertical transmission rate in England has remained <0.4% since 2012. We describe recent trends in characteristics and outcomes of pregnancies in women living with HIV (WLWH) in England in 2015–20.

Materials/Methods

The Integrated Screening Outcomes Surveillance Service (ISOSS), part of the NHS Infectious Diseases in Pregnancy Screening Programme, commissioned by NHSE, conducts population-based surveillance of pregnancies in WLWH. Analyses covered pregnancies in WLWH diagnosed before delivery with a booking date 2015–20, reported by 31/12/2021.

Results

There were 5,116 pregnancies, with annual numbers decreasing from ~1,000 in 2015–16 to 600–700 in 2019–20. The median age at delivery was 34years (IQR: 30,38) with the proportion of pregnancies in women aged ≥40years increasing from 14.3% in 2015 to 19.1% in 2020, p<0.001. Pregnancies in women born in sub-Saharan Africa declined, from 72.0% in 2015 to 61.5% in 2020, while those among women born in Eastern Europe increased from 4.7% to 6.5%, p<0.001. Proportion of pregnancies in women with vertically-acquired HIV increased from 1.5% 2015 to 5.6% in 2020, p<0.01. By 2020, 89.8% (545/600) of pregnancies were in women diagnosed before pregnancy, an increase from 87.9% (974/1108) in 2015 (not significant, p=0.36). The proportion of women on ART at conception increased from 70.1% (693/989) to 83.7% (503/601) (p<0.001). Over the period, >90% of delivery viral loads were undetectable (<50copies/ml) up to 93.4% in 2020. Vaginal delivery rate remained stable at 47.9% in 2020 and the preterm delivery rate remained ~12%. Supported breastfeeding cases increased from 20–30 in 2015–16 to 40–50 in 2019–20.

Discussion

Changes in the population of WLWH accessing antenatal care in England have implications for service provision and require monitoring. Clinical outcomes are reassuring and ISOSS continue to monitor emerging areas of interest including infant feeding and health inequalities.