Gender Differences in Infant Mortality and Neonatal Morbidity in Mixed-Gender Twins

Abstract

In the present study, we aimed to explore gender differences in infant mortality and neonatal morbidity in mixed-gender twin pairs. Data were obtained from the US National Center for Health Statistics Linked Birth-Infant Death Cohort. A total of 108,038 pairs of mixed-gender twins were included in this analysis. Among the mixed-gender twins, no significant difference in the odds of fetal mortality between male twins (1.05%) and female co-twins (1.04%). However, male twins were at increased odds of neonatal mortality (adjusted OR 1.59; 95% CI 1.37, 1.85) and overall infant mortality (adjusted OR 1.43; 95% CI 1.27, 1.61) relative to their female co-twins. Congenital abnormalities (adjusted OR 1.38; 95% CI 1.27, 1.50) were identified significantly more frequently in male than female twins. Moreover, increased odds of having low 5-minute Apgar score (<7) (adjusted OR 1.15; 95% CI 1.05, 1.26), assistant ventilation >30 minutes (adjusted OR 1.31; 95% CI 1.17, 1.47), and respiratory distress syndrome (adjusted OR 1.45; 95% CI 1.26, 1.66) were identified in male twins relative to their female counterparts. The results of our study indicated that in mixed-gender twin pairs, the odds of infant mortality and neonatal morbidity were higher in male twins than their female co-twins.

Vitamin and Mineral Supplementation During Pregnancy on Maternal, Birth, Child Health and Development Outcomes in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

“…Similarly, birth outcomes were typically not disaggregated by sex, which limited this review from conducting subgroup analyses by sex of the infant. This is also an important consideration for future research, as previous evidence suggests differences between female and male infants for certain mortality and morbidity outcomes [33,109,125,126]. Further, a recent review by Smith et al, authors noted a 15% greater reduction in mortality in female infants compared to their male counterparts [43].…”

Neonatal Mortality and Temperature in Two Northern Swedish Rural Parishes, 1860–1899—The Significance of Ethnicity and Gender

“…Compared to season of birth, in which winter was associated with an overall higher mortality risk, this study found no gender difference in seasonality. It can be expected that the negative effect of low temperatures following birth among males is associated with a higher risk of being both preterm and underweight, as these two factors increase the risk of hypothermia [16].…”

“…In nineteenth century Sweden, the indigenous Sami population experienced a higher neonatal mortality rate compared to the non-Sami population, especially during the first half of the century [12,13]. In historical and contemporary populations, the male disadvantage in neonatal mortality is well recognized [14][15][16][17][18] and is essentially explained by biological factors, such as a higher risk of congenital abnormalities among male new-borns relative to females and a higher incidence of infectious and non-infectious diseases in boys [16,17]. There is a lack of research regarding the influence of temperature on neonatal mortality among boys relative to girls.…”

Pre- and Perinatal Characteristics Associated with Apgar Scores in a Review and in a New Study of Dutch Twins

“…Birth weight discordance in twins is associated with low Apgar scores for the second born (Lindroos et al, 2018;Stein et al, 2008). On average, girls have higher Apgar scores than boys (Dolgun et al, 2016;Hegyi et al, 1998;Stevenson et al, 2000;Zhao et al, 2017).…”