Weight gain in pregnancy: is less truly more for mother and infant?

Although more than 50% of women gain weight above the Institute of Medicine (IOM) guidelines for weight gain in pregnancy and excessive weight gain is an independent risk factor for significant maternal and neonatal morbidity and offspring obesity, there is little consensus over the ideal weight gain during pregnancy. Surprisingly, the 2009 IOM guidelines varied minimally from the 1990 IOM guidelines, and many critics advocate lower weight gain recommendations. This review explores the energy costs of pregnancy, the relationship between gestational weight gain and birth weight, and considers what gestational weight gain minimizes both large-for-gestational age as well as small-for-gestational age infants. An extensive examination of the current data leads this author to question whether the current weight gain recommendations are too liberal, especially for obese pregnant women.