OA Epidemiology

Fetal Gender of the First Born and the Recurrent Risk of Spontaneous Preterm Birth

Proceedings of the 2013 annual meeting of the Netherlands Epidemiology Society

Volume 1 Issue S1 Abstract 17


Anita Ravelli, Academisch Medisch Centrum, Amsterdam
Esme Kamphuis, Academisch Medisch Centrum, Amsterdam
Michel Hof, Academisch Medisch Centrum, Amsterdam
Ben Willem Mol, Academisch Medisch Centrum, Amsterdam
Brenda Kazemier, Academisch Medisch Centrum, Amsterdam

The risk of spontaneous preterm birth is, amongst other factors, influenced by fetal gender and a history preterm birth. We studied the impact of these factors on the risk of preterm delivery in the second pregnancy.

We used longitudinal linked data from the Perinatal Registration Netherlands from 1999-2007. We selected Caucasian women who had their first and second child singleton and spontaneously born (n=108.584). Mutivariable logistic Regression analysis was used to estimate the risk of preterm birth in the second pregnancy.

The prevalence of spontaneous preterm birth was 7.7% in the first pregnancy (6.7% among girls and 8.7% among boys) and 3.8% in the second pregnancy (3.3% among girls and 4.3% among boys). For women who delivered at term and preterm in their first pregnancy the preterm birth risk was 2.5% (2.1% for girls versus 2.9% boys) and 19% (17% for girls versus 21% boys), respectively.
Risk for spontaneous preterm birth in the second pregnancy was determined by spontaneous preterm delivery in the first pregnancy  (OR 8.5 (95%CI 7.9-9.1)), pregnancy after ART (OR 3.1, (95% CI 2.9 to 3.4)), short interval (OR 2.7, (95% CI 2.3 to 3.2)), male gender second fetus (OR 1.3 (95% CI 1.3 to 1.4)), low SES (OR 1.2 (95%CI 1.05-1.3)),  but not the gender of the first pregnancy(OR1.0  (95%CI 0.9-1.1)).  Neither gender of the first nor of the second child did interact with preterm birth risk.

Spontaneous preterm delivery is determined by fetal, maternal and environmental components.

Published: 06 Jun, 2013

Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)