Risks of weight gain between babies

Gaining weight between pregnancies may increase the risk of neonatal complications, according to Swedish researchers.

A team at the Karolinska Institutet, Sweden, looked at outcomes for 587,710 women who had at least two babies between 1992 and 2012. Their details were stored in the Swedish Medial Birth Registry.

Neonatal health was recorded for all the infants, including Apgar score five minutes after delivery, and evidence of seizures or severe breathing difficulties during the neonatal period. Analysis indicated that inter-pregnancy weight gain increased risks of these asphyxia-related complications.

Writing in PLoS Medicine the researchers state that the risk of these conditions in a second child is higher if the mother has put on a substantial amount of weight since the birth of her first child.

Researcher Dr Martina Persson says: "We found that weight gain between pregnancies increased the risk of asphyxia in a woman’s second baby. This was particularly salient in children of mothers who were of normal weight at the time of their first pregnancy, but who had put on weight by their second.

"Weight gain between pregnancies also increases risks of other complications related to pregnancy and infant health. The take home message is that after delivery, women should be advised to return to their pre-pregnancy weight," she concludes.

An earlier analysis also showed raised risks of stillbirth and infant mortality. Compared with women with a stable body mass index between pregnancies, those who gained at least four body mass index points between pregnancies had a 55% increased rate of stillbirth and a 29% increased rate of infant mortality. This risk of infant mortality in the second pregnancy only applied to women with a healthy body mass index during the first pregnancy, who became overweight, the researchers say.

Persson, M. et al. Inter-pregnancy Weight Change and Risks of Severe Birth-Asphyxia-Related Outcomes in Singleton Infants Born at Term: A Nationwide Swedish Cohort Study. PLoS Medicine 7 June 2016