Gestational diabetes in women living with HIV in the UK and Ireland: insights from population-based surveillance data.

introductionThe prevalence of gestational diabetes (GD) is increasing globally. While universal risk factors for GD are reasonably well understood, questions remain regarding risks for women living with HIV (WLWH). We aimed to describe GD prevalence, evaluate associated maternal risk factors and assess specific birth outcomes in WLWH in the UK and Ireland.

methodsWe analysed all pregnancies (≥24 weeks' gestation) in women diagnosed with HIV before delivery, reported to the UK-based Integrated Screening Outcomes Surveillance Service between 2010 and 2020. Every report of GD was considered as a case. A multivariable logistic regression model, adjusted for women with more than one pregnancy fitted with generalized estimating equations (GEE) assessed the effect of independent risk factors.

resultsThere were 10,553 pregnancies in 7916 women, of which 460 (4.72%) pregnancies had reported GD. Overall, the median maternal age was 33 years (Q1:29-Q3:37), and 73% of pregnancies were in Black African women. WLWH with GD (WLWH-GD) were older (61% vs. 41% aged ≥35 years, p < 0.001) and more likely to be on treatment at conception (74% vs. 64%, p < 0.001) than women without GD. WLWH-GD were more likely to have a stillbirth (odds ratio [OR]: 5.38, 95% CI: 2.14-13.5), preterm delivery (OR: 2.54, 95% CI: 1.95-3.32) and fetal macrosomia (OR: 1.14, 95% CI: 1.04-1.24). Independent risk factors for GD included estimated year of delivery (GEE-adjusted odds ratio [GEE-aOR]: 1.14, 95% CI: 1.10-1.18), advanced maternal age (≥35 years) (GEE-aOR: 2.87, 95% CI: 1.54-5.34), Asian (GEE-aOR: 2.63, 95% CI: 1.40-4.63) and Black African (GEE-aOR: 1.55, 95% CI: 1.13-2.12) ethnicity. Timing and type of antiretroviral therapy showed no evidence of a relationship with GD in multivariable analyses; however, women with a CD4 count ≤350 cells/μl were 27% less likely to have GD than women with CD4 counts >350 cells/μl (GEE-aOR: 0.73, 95% CI: 0.50-0.96).

conclusionsGD prevalence increased over time among WLWH but was not significantly different from the general population. Maternal age, ethnicity and CD4 count were risk factors based on available data. Stillbirth and preterm delivery were more common in WLWH-GD than other WLWH over the study period. Further studies are required to build upon these results.