Epidemiology and biostatistics assistant professor, Dr. Nansi Boghossian and associate professor Dr. Marco Geraci (University of South Carolina Arnold School of Public Health) have collaborated with researchers at the University of Vermont to complete a study on the sex differences in mortality and morbidity of infants born at less than 30 weeks’ gestation. Their paper was published in the journal, Pediatrics.
With this study, the researchers aimed to examine whether changes in mortality and morbidities have benefited male more than female infants. They studied the outcomes of more than 205,000 infants born between 22 and 29 weeks gestational age at a U.S. Vermont Oxford Network Center between January 2006 and December 2016.
Drs. Boghossian and Geraci and their team looked at mortality and morbidity rate differences and 95 percent confidence intervals by sex and birth year. They tested temporal differences in mortality and morbidity rates between boys and girls by means of a likelihood ratio test on nested binomial regression models with log links.
The authors found that the rate for mortality, respiratory distress syndrome, and chronic lung disease decreased faster for boys than for girls over an 11-year period. Morbidities, including patent ductus arteriosus, necrotizing enterocolitis, early-onset sepsis, late-onset sepsis, severe intraventricular hemorrhage, severe retinopathy of prematurity, and pneumothorax, revealed a constant rate difference between boys and girls over time.
The authors recommend that research investigate which causes of death declined among boys and whether their improved survival has been accompanied by a change in their neurodevelopmental impairment rate.