Perinatal outcomes, maternal age, parity and fetal sex – searching for the "optimal" maternal age
Background: Maternal age, parity and fetal sex are each known to affect obstetric and birth outcomes. The objective of the present study was to investigate the influence of the combination of maternal age, parity and fetal sex on outcomes of pregnancies. The aim of the study was to analyze the influence of maternal age on perinatal outcomes in both primiparous and multiparous women with different fetal sex. Methods: The cross-sectional study was performed on data from 11,780 women, who have given birth at the General University Hospital in Prague, Czech Republic between 2008-2012. Results: Maternal age significantly (P<0.01) influenced pregnancy weight gain, duration of pregnancy, birth weight and birth length. Primiparous women with female newborns aged ≤19 had higher rates of preterm delivery than comparable women 20-39 (P=0.012). Similarly, women with male newborns aged ≥40 had higher rates of preterm delivery than comparable women 20-39 (P=0.003). Women aged ≤24 expressed higher rates of low birth weight than women aged >24 (P<0.001), regardless of parity and fetal sex. The older (≥35) primiparous women with male newborns expressed a higher incidence of macrosomia (P=0.021) compared to other groups of women. The probability of caesarean delivery increased with age (P<0.001) and it was significantly affected by the parity and sex of the newborn with higher rates of caesarean section in primiparous women as well as in mothers carrying male fetuses. Conclusions: Our results indicate that optimal maternal age without obstetrics and birth complications is 25-34 years, older age is associated with increased complications with a male fetus, especially in primiparous women. Our data suggests that not just the age of women, but the combination of age, parity, and fetal sex should be taken into consideration during assessment of health risks of pregnancy.