Linear association between maternal age and spontaneous breech presentation in singleton pregnancies after 32 weeks...

To investigate the association between maternal age and spontaneous breech presentation.

Fifteen-year observational study over (2001-2015). All consecutive singleton births delivered at the Centre Hospitalier Universitaire Sud Reunion's maternity. The only single exclusion criterion was uterine malformations (N = 123) women.

Of the 60,963 singleton births, there was a linear association (χ² for linear trend, p< 0.0001) between maternal age and spontaneous breech presentation. Overall rate of breech presentation was 2.7% in deliveries over 32 weeks gestation, while it was 1.9% in women aged 15 to 19 years and 4.0% in women aged 45+, with a linear progression for each 5-year age category. This linearity remained significant controlling for early prematurity (<33 weeks) and severe fetal malformations (χ² for linear trend = 64, p < 0.0001). Controlling in a multiple logistic regression model for other major risk factors gestational age, female sex, primiparity, maternal age remained significantly an independent risk factor, p < 0.0001.

Maternal age (x) is an independent factor for breech presentation in singleton pregnancies after 32 weeks gestation with a linear association that may be approximated at y = 0.1x. (y: incidence, percent).