Objectives

We assessed real-world weight change and pregnancy outcomes among pregnant women living with HIV who used integrase strand transferase inhibitor (INSTI)-based combined antiretroviral therapy (cART).

Methods

In a retrospective cohort study from 2014 to 2021 for prevention of perinatal HIV infection, we evaluated changes in weight from the first prenatal visit to near delivery for two groups. The categories of change were: low (< 0.18 kg/week), normal (0.18-0.59 kg/week), and high (> 0.59 kg/week). The backbones were lamivudine + tenofovir disoproxil or lamivudine + zidovudine. The comparison groups were women with body mass index (BMI) < 25 kg/m² versus BMI ≥ 25 kg/m² and INSTI-naïve versus INSTI-experienced. Continuous variables were analysed with a Kruskal-Wallis test and count or categorical data with χ² tests.

Results

We enrolled 198 pregnant women. At study entry, 74 had BMI < 25 kg/m² and 124 had BMI ≥ 25 kg/m² . Excess gestational weight gain was more frequent among women who were INSTI-naïve among both BMI groups (< 25 and ≥ 25). However, the proportion of participants per weight change category was only significantly different between INSTI-naïve women with baseline BMI < 25 kg/m² and INSTI-experienced women with BMI < 25 kg/m² . In particular, INSTI-naïve women with BMI < 25 kg/m² had significantly higher rates of excess gestational weight gain (31.6%) compared with participants with BMI < 25 kg/m² who conceived while on INSTIs (11.8%, p = 0.004). Rates of unfavourable pregnancy outcomes were low and did not differ significantly between groups.

Conclusions

INSTI-naïve participants with BMI < 25 kg/m² gained more weight during pregnancy than participants with BMI ≥ 25 kg/m² who conceived while using INSTIs. Rates of adverse pregnancy outcomes did not differ between the groups.