Effects of Integrase Strand Transfer Inhibitors Versus Non-INSTI Regimen Exposures in Pregnancy Outcomes, Maternal Weight Gain, and Human Immunodeficiency Virus Viral Suppression

<b><i>Background:</i></b> Integrase strand transfer inhibitors (INSTIs) with and without tenofovir alafenamide fumarate (TAF) are recommended in first-line regimens for pregnant people living with human immunodeficiency virus (PWH), with mixed data emerging on pregnancy outcomes and maternal weight gain. <b><i>Methods:</i></b> This is a retrospective cohort study across two academic medical centers from January 2014 to April 2024. PWH were divided by antiretroviral treatment exposure into INSTI and non-INSTI groups as well as into TAF exposure and nonexposure groups. Maternal and neonatal demographics and outcomes were collected. Continuous variables were analyzed with Student's <i>t-</i>test, whereas categorical variables were compared using Chi-square and Wilcoxon rank-sum test. <i>p</i>-Values of <0.05 were considered significant. <b><i>Results:</i></b> Of 401 PWH, 118 PWH received INSTI with TAF regimens; 130 had INSTI without TAF-exposures; 14 had TAF without INSTI-exposure; and 136 had a non-INSTI and non-TAF regimen. INSTI (with TAF)-exposed individuals were older than those without INSTI exposure, but otherwise had similar baseline demographics. In multivariable analysis, TAF exposure (with and without INSTI) was associated with higher odds of undetectable viral load at delivery (aOR: 4.30, 95% confidence interval 2.41-7.65). Neither INSTI- (with and without TAF) nor TAF (with and without INSTI)-exposed individuals had significantly higher odds of PTB. Any TAF exposure also had greater odds of hypertensive disorder of pregnancy at delivery. There were no differences in total maternal weight gain by either INSTI or TAF exposure. <b><i>Conclusion:</i></b> Any INSTI exposure did not significantly increase odds of undetectable viral load at delivery. Any TAF exposure was significantly associated with undetectable viral load and hypertensive disorder at delivery.