Repeat Pregnancies Among US Women Living With HIV in the SMARTT Study: Temporal Changes in HIV Disease Status and Predictors of Preterm Birth

BACKGROUND: Birth rates among women living with HIV (WLHIV) have increased recently, with many experiencing multiple pregnancies. Yet, viral suppression is often not sustained between pregnancies. In addition, protease inhibitors (PIs) have been associated with preterm birth, but associations between integrase strand transfer inhibitors (INSTIs) and preterm birth are less well characterized. METHODS: We studied WLHIV with ≥2 live-born infants enrolled into the Pediatric HIV/AIDS Cohort Study Surveillance Monitoring for Antiretroviral Treatment Toxicities (SMARTT) study between 2007 and 2018, comparing CD4 counts and viral loads (VLs) between 2 consecutive SMARTT pregnancies. We evaluated associations of covariates with CD4 and viral suppression and the association of PI/INSTI use during pregnancy with odds of preterm birth. RESULTS: There were 736 women who had ≥2 live-born children enrolled in SMARTT (1695 pregnancies). Median CD4 counts remained stable over repeat pregnancies. Although >80% of women achieved VL suppression during pregnancy, more than half had a detectable VL early in their subsequent pregnancy. In adjusted models including all singleton pregnancies, an increased odds of preterm birth was observed for women with first trimester PI initiation (adjusted odds ratio: 1.97; 95% confidence interval: 1.27 to 3.07) compared with those not receiving PIs during pregnancy and for first trimester INSTI initiation (adjusted odds ratio: 2.39; 95% confidence interval: 1.04 to 5.46) compared with those never using INSTIs during pregnancy. CONCLUSIONS: Most WLHIV achieved VL suppression by late pregnancy but many were viremic early in subsequent pregnancies. First trimester initiation of PIs or INSTIs was associated with a higher risk of preterm birth.