The high prevalence of maternal overweight and obesity may have implications for infant health, as pregnancy complications such as pre-eclampsia and diabetic disorders are more common in these women.1 Maternal weight change between consecutive pregnancies correlates linearly with risks of these obesity related pregnancy complications, suggesting a causal relationship. Pre-eclampsia is associated with intrauterine growth restriction and preterm delivery. Diabetic disorders increase the risk of congenital anomalies and may lead to macrosomia that increases the risk of birth trauma.4-6 Pregnancy complications probably explain the obesity related increased risk of medically indicated preterm delivery, but obese women are also at increased risk of spontaneous extremely preterm delivery (≤27 completed
weeks).
Research on associations between maternal body mass index
(BMI) and infant mortality has not produced consistent results.
Two recently published meta-analyses disagree on whether
infants of overweight mothers (BMI 25.0–29.9) are at increased
risk,8 9 and only one of these meta-analyses investigated risks
during the neonatal period.9 Other studies disagree on whether
there are ethnic differences.10 11 Maternal obesity is known to
increase the risk of infant deaths due to congenital anomalies,12
but research on associations with other specific causes of infant
mortality is scarce.