Diabetes and hypertension in pregnancy: Association with adverse birth outcomes among pregnant women living with and without HIV in Cape Town, South Africa (2017-2019): A retrospective study
Background Research suggests that human immunodeficiency virus (HIV) and antiretroviral therapy (ART) increases the likelihood of having hypertension and diabetes. In pregnancy, maternal exposures such as HIV and ART, hypertension, and diabetes are associated with adverse birth outcomes. However, studies tend to explore these factors in isolation. In South Africa, there is a high prevalence of HIV and obesity, thus a high risk of hypertension and diabetes. This study sought to explore the interplay of these non-communicable diseases (NCDs) with HIV in pregnancy and the prevalence of adverse birth outcomes. Methods A retrospective secondary data analysis of data collected from pregnant women where questionnaires, body anthropometrics and birth outcomes were obtained in an urban antenatal facility was conducted. A total of 470 (48%) participants living with HIV and 505 (52%) without HIV were included in this analysis. The prevalence of hypertension and diabetes was reported as overall and stratified by body mass index (BMI) and HIV status in the population. Pregnancy exposures of interest were HIV, hypertension, diabetes, HIV and hypertension, HIV and diabetes, and ART initiated during and pre-pregnancy. Factors associated with hypertension and diabetes were assessed using regression analysis although we could not retrieve the models on diabetes due to sample size restrictions. The adverse birth outcomes of interest were small for gestational age (SGA), large for gestational age (LGA), preterm delivery (PTD), low birthweight (LBW), and high birthweight (HBW). Median and interquartile range, proportions, and regression analysis were used to analyse adverse birth outcomes. Results Overall hypertension was approximately 9% whereas diabetes was 2% in this population. Although we could not achieve statistical significance, obese women living with HIV (WLHIV) had higher hypertension prevalence compared to normal weight WLHIV (14% vs 2%). A unit increase in gravidity, parity and age were significantly associated with increased odds of having hypertension (gravidity OR 1.02; 95% confidence interval (CI): 1.01 – 1.04, parity OR 1.02; 95% CI: 1.01 – 1.04, age OR 95% CI: 1.00 – 1.01). Being obese was significantly associated with increased odds of having hypertension (OR 1.07; 95% CI: 1.02 – 1.13). While there were some associations between increased LBW, PTD and SGA and HIV and ART initiation timing, statistical significance could not be achieved. Hypertension was significantly associated with more LBW and PTD (LBW aOR 2.05; 95% CI: 1.14 – 3.68, PTD aOR 4.67; 95% CI: 2.63 - 8.15). WLHIV and diabetes had a significantly higher prevalence of PTD (26% vs 9%) compared to WLHIV only. There were no appreciable differences in the prevalence of diabetes by HIV status. Stratifying by BMI, total diabetes was significantly higher in the obese group (3%) compared to the normal weight (1%) and overweight group (1%). LBW prevalence was significantly higher in diabetic pregnancies than in non-diabetic pregnancies (30% vs 10%). A higher SGA, LGA, HBW and LBW were recorded for WLHIV and diabetes compared to WLHIV only (SGA: 43% vs 11%, LGA 28% vs 8%: HBW: 14% vs 4%, LBW: 43% vs 11%). Conclusion The findings suggest that a double burden of HIV plus an additional non-communicable disease needs to be closely monitored to prevent increased poor birth outcomes. Extensive dietary and physical activity plans need to be incorporated to mitigate the occurrence of NCDs and poor birth outcomes in this high BMI population especially in WLHIV. The prevalence of diabetes and hypertension in WLHIV needs to be further studied, especially in the HIV-burdened Southern African settings.
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Department of Public Health and Family Medicine