Comorbidities in pregnant South African women living with HIV and associations with adverse birth outcomes: a prospective cohort study.

Background: Despite improved health and survival due to lifelong antiretroviral therapy (ART), women living with HIV (WHIV) still face lower life expectancy, partly due to increased non-communicable disease (NCD) risk. Both HIV and NCDs are linked to adverse birth outcomes, yet data on their combined impact are limited. We investigated NCD burden by HIV status and compared adverse birth outcomes in pregnant WHIV only versus HIV-NCD comorbidity in Cape Town, South Africa.

Methods: Pregnant WHIV (n = 479) and without HIV (n = 510) were enrolled and prospectively followed for pregnancy outcome. Weight and height measurements were serially collected by a study nurse, and diagnoses of hypertension and diabetes mellitus (DM) were made by healthcare providers as part of routine care (ANC). Birth outcomes were abstracted from health records. Proportions described adverse outcomes between groups. Logistic regression was used to estimate associations between HIV and HIV-NCD with small for gestational age (SGA), large for gestational age (LGA), preterm delivery (PTD), low birthweight (LBW), and high birthweight (HBW) (reference: group with neither HIV nor NCDs).

Results: Among 989 pregnant women, 48% (n = 479) with HIV (median age 29 years, IQR 25-34), the prevalence of obesity (BMI ≥ 30 kg/m²) was 43%, hypertension 15% and DM 2%. The NCD prevalence did not differ by HIV status. HIV co-occurred with obesity in 31% of pregnancies, with hypertension in 5% and with DM in 0.2%. HIV with hypertension and HIV with hypertension and obesity were associated with increased odds of PTD compared to those with neither HIV-NCD (aOR 3.03, 95% CI 1.01, 8.05 and aOR 2.67, 95% CI 1.08, 6.23, respectively). However, HIV and obesity together were associated with lower odds of SGA (aOR 0.39, 95% CI 0.16, 0.97). Likewise, in women without HIV, obesity protected against SGA and LBW, but hypertension increased PTD and LBW.

Conclusion: There was no difference in the prevalence of NCD in pregnant women by HIV status. Increased risk of adverse birth outcomes was demonstrated with concurrent NCD regardless of HIV status. Integration of NCD screening and management within ANC could minimise excess adverse outcomes in high HIV burden settings.