OBJECTIVE: To identify independent risk modifiers of and develop a prediction model for preterm births for pregnant people living with HIV. METHODS: We analyzed the British Columbia Perinatal HIV Surveillance Database for singleton births from January 1997 to December 2022. Risk modifiers for preterm birth (< 37 weeks gestational age) were identified through univariate analyses. We then completed a multivariate logistic regression using clinically relevant risk factors and risk modifiers with p-value < 0.1 in the univariate analysis. Using stepwise regression with Akaike information criterion, the prediction model was developed. RESULTS: Of 578 singleton pregnancies in pregnant people living with HIV (PLWH), 111 (19.2%) had preterm births. After adjusting for history of preterm birth, CD4 count at delivery, and antiretroviral regimens, independent risk factors include substance use in pregnancy (OR: 1.9; 95% CI: 1.03-3.50; p=0.041), Hepatitis C in pregnancy (OR: 1.98; 95% CI: 1.02-3.83; p=0.043), unsuppressed viral load at delivery (OR: 2.03; 95% CI: 1.09-3.79; p = 0.026) and sexually transmitted infections or bacterial vaginosis (STIBV) in pregnancy (OR: 2.06; 95% CI: 1.04 – 4.10; p = 0.039). A prediction model with substance use, STIBV, hepatitis C in pregnancy, unsuppressed viral load, and low CD4 count was developed (AUC = 0.73). For PLWH without any risk factors, the predicted probability of preterm birth is 9%. CONCLUSIONS: Independent risk factors associated with preterm births in PLWH include substance use in pregnancy, unsuppressed viral load, Hepatitis C co-infection, and sexually transmitted infections or bacterial vaginosis in pregnancy.
Wong et al. (Wed,) studied this question.