Obesity prevention begins during pregnancy

The more weight a woman gains during pregnancy, the heavier her baby will be at birth, regardless of genetic factors, according to a population-based cohort study of more than 500,000 women from Michigan and New Jersey. Each additional kilogram gained by the mother increases her baby's birth weight by about 7.35 g.

Researchers found that the infants of women who gained more than 24 kg during pregnancy were a mean 148.9 g heavier at birth than were infants of women who gained 8 to 10 kg. The odds ratio of giving birth to an infant weighing more than 4,000 g was more than double (2.26) for women who gained more than 24 kg during pregnancy compared with women who gained 8 to 10 kg.

Given that high birth weight predicts body mass index later in life, this study suggests that excessive maternal weight gain increases the long-term risk for obesity and its related diseases later in the life of offspring.