Recurrence of preterm births

A recent retrospective study investigated the recurrence of preterm birth (PTB) among the poorest half of the Brazilian population.

It utilized the data about the live births of multiparous women extracted from the CIDACS Birth Cohort between 2001 and 2015. The study used multivariate logistic regression to estimate the odds of recurrent PTB in second and third births.

The observations of the study were as follows-

• It analyzed 3528050 live births from 1764025 multiparous women. 
• It found the adjusted odds for a PTB occurrence, given a previous PTB, as 2.58. 
• Lower gestational age increases the odds of a subsequent PTB (<28 weeks: adjusted OR [aOR] 3.61; 28–31 weeks: aOR 3.34; and 32–36 weeks: aOR 2.42). 
• Women with two previous PTBs possess an even high risk of having a third (aOR 4.98). 
• The inter-birth interval of <12 months increases the probability of the recurrence of PTB.

This study explains that women with a previous PTB have an increased risk of a subsequent one, and this association is affected by gestational age, the number of PTBs, the severity of previous PTBs, and a short interval between births.

Rocha AS, Ribeiro-Silva R de C, Paixao ES, et al. Recurrence of preterm births: A population-based linkage with 3.5 million live births from the CIDACS Birth Cohort. International Journal of Gynecology and Obstetrics. 2022;158(3): 605-612. https://doi.org/10.1002/ijgo.14053