Background: Recent data suggests clinically significant weight gain among non-pregnant HIV-infected adults after starting dolutegravir-based ART (DTG). Excess or inadequate weight gain in pregnancy could adversely impact maternal and fetal outcomes, but data for pregnant women receiving DTG has been limited to date.
Methods: The Tsepamo Study captured data at up to 18 large delivery sites in Botswana from August 2014-March 2019. Pre-pregnancy weight, weight measurements during antenatal care (ANC), HIV testing and HIV treatment information were abstracted at delivery from the maternity obstetric record. HIV-positive pregnant women who initiated DTG or EFV between conception and 17 weeks gestation and HIV-negative women with similar ages who presented for ANC care before 17 weeks gestation were included in this analysis. We evaluated weekly weight gain and total 18-week weight gain between 18±2 and 36±2 weeks gestation by exposure group. Linear regression models estimated mean differences, adjusting for demographic and clinical variables.
Results: Women initiating DTG and EFV had similar baseline characteristics, including pre-pregnancy weight and weight at ART initiation. Compared to EFV, the adjusted mean weekly weight gain was 0.05 (95% CI 0.03, 0.07) kg/week higher and the adjusted mean 18-week weight gain was 1.12 (95% CI 0.67, 1.57) kg higher for DTG. The weight gains in both ART groups were less than the weight gains in HIV-negative women (Table). Differences in weight gain by ART regimen were larger among women weighing >80kg and were attenuated among women weighing < 50kg before ART initiation.

 EFV (n=1,683)DTG (n=1,464)HIV-negative (n=21,917)
Age, mean28.828.928.3
Pre-pregnancy weight, mean62.60kg62.80kg63.01kg
Weight at ART initiation, mean65.62kg65.66kg66.51kg (at first ANC)
Primigravid, percent29.1%26.6%32.7%
Pre-ART CD4 cell count, mean419 cells/µl390 cells/µl--
Weekly weight gain, mean0.31kg/week0.35kg/week0.44kg/week
Adjusted mean difference (95% CI)reference0.05 (0.03, 0.07) kg/week0.12 (0.10, 0.15) kg/week
18-week weight gain, mean5.30kg6.27kg7.95kg
Adjusted mean difference (95% CI)reference1.12 (0.67, 1.57) kg2.42 (1.92, 2.91) kg
[Baseline characteristics and weight gain during pregnancy by exposure group, The Tsepamo Study]

Conclusions: Women initiating DTG compared with EFV during pregnancy gained more weight between 18 and 36 weeks gestation, particularly among those with higher pre-ART pregnancy weight. However, neither group gained as much weight as HIV-negative women. Further research is needed to understand the impact of weight gain differences on maternal and infant outcomes.

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