Sex related difference in cardiac output during neonatal tra
This is the first study to demonstrate a sex-related difference in cardiac output in healthy term neonates during the immediate transition after birth. Male neonates had a higher cardiac output compared to female neonates 15 minutes after birth. This observation contributes that cardio-circulation has sex-related differences already immediately after birth in healthy term neonates. Further investigations of our group focus on preterm neonates and neonates in need of medical support and resuscitation, where these differences might affect necessary clinical interventions.

The immediate transition from fetus to neonate includes substantial changes especially concerning the cardiovascular system. As sex related differences have been shown in cardiovascular medicine, this topic warrants further investigation in neonatology. The aim of this present study was to measure cardiac output and cerebral oxygenation (cTOI) non-invasively in term neonates and to investigate potential sex related differences between female and male neonates after birth.

This is a mono-centric prospective observational study. For CO measurements, the electrical velocimetry method was used. 99 term neonates were enrolled. In our study population, we could identify 54 female and 45 male neonates. Males had higher cardiac output compared to females throughout the observational period, with a significant difference in minute 15 after birth. cTOI, SpO2, and HR did not differ between male and female neonates.