Recurrence of Preterm Delivery in Women with a Family History of Preterm Delivery.

This study aims to evaluate the role of a family history of preterm delivery on the risk of preterm delivery in the next generation.  A retrospective population-based study was conducted. Perinatal information was gathered from 2,303 familial triads, composed of mothers (F), daughters (F), and children (F). All births occurred in the same regional medical center between the years 1991 and 2013. Statistical analysis using logistic regression was performed to define the risk of F delivering a preterm baby (F) if she was born preterm herself, and then to define the risk of F delivering preterm if her mother (F) gave birth preterm during any of her birthing events.  The risk for preterm delivery of the F parturient was 34% greater if their mother (F) at any of her births had delivered preterm, controlling for parity, maternal age at delivery, and preeclampsia (adjusted odds ratio: 1.34, 95% confidence interval: -1.01 to 1.77;  = 0.042).  The family history of preterm delivery is an independent risk factor for preterm delivery. The family history includes the mother as well as one of the mother's sisters (F generation) being born preterm.