Maternal weight gain between pregnancies is linked to complications and adverse outcomes

The researchers examined data from the nationwide Swedish Medical Birth Register, including 532,858 second-born infants born at term (greater than or equal to 37 weeks gestation) to mothers having their first and second infants between 1992 and 2012. Compared with mothers with stable weight (-1 to <1 kg/m² change in BMI between pregnancies), they observed that infants born to mothers who gained 4 kg/m² or more between pregnancies had a 33% to 78% increased risk of low Apgar score (a measure of newborn health), neonatal seizures, and meconium aspiration.

While the researchers could not investigate the potential impact of obstetric and neonatal interventions and did not have information when the weight gain occurred or on gestational weight gain, the findings provided suggest that preventing weight gain between pregnancies could reduce the risk of birth asphyxia and improve infant health.

The authors say: "Encouraging women to normalize BMI before pregnancy and to avoid weight gain between pregnancies is likely to be an important measure to improve infant health."