Neonatal outcomes in relation to sex differences: a national cohort survey in Taiwan

Abstract

BackgroundAn extensive assessment investigating the association between sex differences and neonatal outcomes is lacking. In the current study, we estimated the correlation of gender with adverse birth outcomes in a large cohort population.MethodsNational population-based data containing maternal and neonatal information in 2001 to 2010 were derived from the Health Promotion Administration, Taiwan. Singletons without high-risk pregnancy were further analyzed for the sex ratio of live births in relation to neonatal outcomes—including preterm birth, birth weight, neonatal death, delivery mode, and congenital anomaly. A multivariate logistic regression model was used to adjust for possible confounders.ResultsIn total, 2,123,100 births were valid for the analysis. Overall, the sex ratio at birth (male/female) was 1.096. Compared to multiple births, the sex ratio was significantly higher with singleton births (p < 0.001). Among multiple births, the incidence of stillbirths was significantly higher in males than in females (p < 0.05). The sex ratio at gestational age (GA) <37 weeks was 1.332, and it declined proportionally with a rise in the GA to 0.899 at GA of ≥41 weeks. In contrast, the sex ratio was 0.850 at birth weight <3000 g, and it rose proportionally with a rise in the birth weight to 1.902 at birth weight ≥4000 g (macrosomia). Operative delivery was more common in males than in females (p < 0.001). The regression analysis showed greater risks of preterm birth, macrosomia, operative delivery, neonatal death, and congenital anomaly among male newborns.ConclusionsMale gender carried higher risks of adverse neonatal outcomes, including preterm birth, macrosomia, operative delivery, neonatal death, and congenital anomaly. The data have clinical implications on health surveillance for plotting strategies in response to the unbalanced sex ratio in relation to the boy preference.

Gestational age-specific sex difference in mortality and morbidities of preterm infants: A nationwide study

“…In contrast to previous studies 15, 16, 29 , the present study performed subgroup analysis according to gestational age and could suggest that male infants have a higher risk for BPD and combined morbidities under 25 weeks of gestation. Furthermore, male infants present specific pattern of risk for each outcome with increasing gestational age.…”

Diagnostic Performance of Cerebroplacental Ratio Thresholds at Term for Prediction of Low Birthweight and Adverse Intrapartum and Neonatal Outcomes in a Term, Low-Risk Population

“…Other authors have reported higher proportions of male fetuses with perinatal complications such as non-reassuring intrapartum FHR patterns, operative delivery [25], preterm birth, low 5-min Apgar score, and neonatal death [26]. Sub-analysis suggests that the skew towards worse outcomes for female fetuses appear to be caused by the higher proportion of female fetuses (66.6 vs. 33.3%, p < 0.01, respectively) with abnormal cord gases, despite almost equal proportions of sexes (49.2 vs. 50.8%, respectively) tested.…”

Expression patterns of the chromosome 21 MicroRNA cluster (miR-99a, miR-125b and let-7c) in chorioamniotic membranes

“…Fetal gender is known to be associated with adverse pregnancy outcomes [18,19]. Male (n = 12) and female (n = 8) fetal subjects in the study were compared with respect to miRNA expression (log 2 qPCR estimates) for each miRNA for each of the 6 groups or sampling sites.…”