Impact of fetal gender on the risk of preterm birth, a national cohort study.

Peelen et al, Acta Obstet Gynecol Scand. 2016 May 24


INTRODUCTION: Fetal gender is associated with preterm birth, however a proper subdivision by onset of labor and corresponding neonatal outcome by week of gestation is lacking.

RESULTS:The study population comprised 1 736 615 singleton deliveries (25+0 -42+6 weeks). Male fetuses were at increased risk of spontaneous preterm b

Moth­er and new­born baby

irth with intact membranes compared to a female fetus with a peak between 27–31 weeks (RR 1.5; 95% CI 1.4–1.6). Male fetuses were also at increased risk of preterm premature rupture of membranes between 27 and 37 weeks (RR 1.2; 95%CI 1.16–1.23). No gender effect was seen for medically indicated preterm birth. No significant differences were seen for neonatal mortality. Males were at significantly increased risk of composite neonatal morbidity from 29 weeks onwards (RR 1.3; 95% CI 1.3–1.4).

CONCLUSIONS: Male fetal gender is a relevant risk factor for spontaneous preterm birth, both for intact membranes and for preterm prematurerupture of membranes in white European women. In addition, male infants are at increased risk of neonatal morbidity. This article is protected by copyright.