Maternal characteristics of preterm singleton birth following assisted reproduction: a population-based study.

Objective: To identify pregestational maternal characteristics that are associated with an increased risk for preterm births (PTB) of assisted reproductive technology (ART) singleton pregnancies.

Patients And Methods: We evaluated the Slovenian National Perinatal Information System (NPIS). We included all ART singletons born during the period 2006-2015. We compared births before and after 36 completed weeks' gestation for maternal age, parity, prepregnancy BMI, height, previous PTB, preexisting hypertension and diabetes, and history of uterine gynecological operations.

Results: Chronic hypertension (OR 2.5, 95% CI 1.3-4.8), previous preterm birth (OR 2.4, 95% CI 1.5-3.7), pregravid obesity (OR 1.6, 95% CI 1.2-2.1) and an existing indication for cerclage (OR 6.2, 95% CI 3.7-10.5) were associated with an increased risk of PTB.

Conclusions: Chronic hypertension, previous PTB, pregravid obesity and an existing indication for cerclage are associated with increased risk of PTB among ART pregnancies.