The role of family history of preterm delivery in the individual risk of spontaneous preterm delivery: a case-control study.

Purpose: To investigate the role of family history of preterm delivery (PTD) in the individual risk of spontaneous preterm delivery.

Methods: A retrospective case-control study was conducted on 354 patients who delivered between 2018 and 2020. 177 women who delivered preterm were matched with 177 controls who had full-term delivery. A questionnaire was administered to investigate the family history of PTD of both the patient and her partner. Cases and controls were matched for the anamnestic risk factors for PTD.

Results: Seventeen of 173 women (9.8%) in the PTD group reported being born preterm, compared to five of 169 women (2.9%) in the control group (p = 0.01), with an odds ratio (OR) of 3.57 (95% confidence interval, CI 1.29-9.92). Women who delivered preterm also reported more frequently having a sibling who was born preterm (12.4% vs. 4.2%, p = 0.01), with an OR of 3.18 (95% CI 1.31-7.7). No association was found between the partner's family history of premature delivery and the patient's risk of preterm delivery in the present pregnancy.

Conclusions: Pregnant patients who were born prematurely or who have siblings born preterm have an increased risk of preterm delivery in their own pregnancies. Assessment of female personal and family history of PTD should be used to identify women at risk of having a PTD in the present pregnancy.