In-hospital mortality and morbidity among extremely preterm infants in relation to maternal body mass index

Area of Science:

• Neonatal research
• Perinatal epidemiology
• Maternal-fetal medicine

Background:

• Maternal body mass index (BMI) is a critical factor in pregnancy outcomes.
• Extremely preterm infants face significant risks for mortality and morbidity.
• Understanding the impact of maternal BMI on extremely preterm infant outcomes is crucial for clinical guidance.

Purpose of the Study:

• To compare in-hospital survival and survival without major morbidities in extremely preterm infants based on maternal prepregnancy BMI.
• To investigate the association between maternal BMI categories (underweight, normal, overweight, obese) and infant outcomes.
• To determine the relationship between increasing maternal BMI and the odds of infant survival.

Main Methods:

• Retrospective cohort study of extremely preterm infants (gestational age 22 0/7–28 6/7 weeks).
• Data collected from National Institute of Child Health and Human Development Neonatal Research Network sites.
• Primary outcome: survival without any major morbidity. Secondary outcome: in-hospital survival.

Main Results:

• No significant difference in survival without major morbidity across maternal BMI groups (underweight/normal, overweight, obese).
• In-hospital survival was lower in the obese maternal BMI group compared to the overweight group (76.5% vs 83.2%).
• Each unit increase in maternal BMI was associated with decreased odds of infant survival (P < 0.01).

Conclusions:

• Maternal obesity is not associated with survival without major morbidity in extremely preterm infants.
• Increased maternal prepregnancy BMI is associated with decreased odds of infant survival.
• Maternal BMI is an important factor influencing survival outcomes in extremely preterm infants.