Sex Differences in Foetal Biometry, New-born Size and Birth Outcome

Abstract

AbstractThis retrospective study analyses sex differences in foetal biometry from the 1st trimester onwards, and sexual dimorphism in newborn size of 4260 singleton term births taking place at the Viennese Danube hospital between 2005 and 2013. Crown-rump length was determined at the 11th to 12th week, biparietal diameter, fronto-occipital diameter, head circumference, abdominal transverse diameter, abdominal anterior-posterior diameter, abdominal circumference and femur length were determined at the 20th or 21st gestational week and at the 32nd or 33rd week of gestation. Immediately after birth, birthweight, birth length and head circumference were taken, the Apgar scores 1, 5 and 10 minutes after birth were determined. Significant sex differences were found from the first trimester onwards. With exception of femur length, male foetuses exhibited always the significantly larger dimensions. At the time of birth, male newborns were significantly larger and heavier than their female counterparts. Sex had an...