Demographic changes and effects on the mode of delivery: a retrospective analysis of a large birth registry containing 27,729 singleton deliveries in a level I center.

To characterize and understand the demographics (age and body mass index, BMI) of a cohort of women who delivered at a single institution over an 11-year period. The purpose of this analysis is to look for effects over time of demographic characteristics on mode of delivery. Retrospective analysis of singleton deliveries between 2004-2014, n = 27,729; level 1 perinatal center, university hospital setting. Data were extracted from the digital birth registry. All statistical analyses were done using R version 3.5.1. Variables analyzed were: age, BMI, and mode of delivery (in the current and any prior pregnancies). Mean age increased from 31.1 ± 5.2 years in 2004 to 31.5 ± 5.0 years in 2014 (p < 0.001, eta Increase of age and BMI over years is significant, but very small and in a range which seems not clinically relevant. Previous births have the strongest effects on mode of delivery in the current pregnancy.