[Nutritional characteristics of newborns of overweight and obese mothers]

Maternal nutritional status is an important factor of adequate intrauterine growth and neonatal weight. The aim of this study is to evaluate the relationship between pre-gestational BMI (Body Mass Index) and breastfeeding duration, as well as infant anthropometric measurements during their first six months of life.

Anthropometric measurements and the type of feeding were evaluated in a representative sample of 1,547 newborns from our population during 2009, according to their maternal BMI, and also in a sub-cohort of 759 infants followed up to 6 months of life.

A total of 72.9% of women had a normal weight, 18.7% were overweight and 8.4% obese. Women with a BMI ≥ 25 kg/m(2) had lower weight gain during pregnancy (P < .001), lower socioeconomic and cultural level (P < .001), and their infants had higher weight at delivery (P=.003) and at 6 months of life, with no differences in body length. Newborn weight increased in relation to maternal BMI, but over 35 kg/m(2) it decreased progressively (P < .001). Breastfeeding prevalence in obese women was 58.5% at hospital postpartum discharge, and 8.6% at six months of life; as opposed to 70.8% and 13.9%, respectively in women with normal BMI.

In our sample, maternal obesity is associated with a low socioeconomic and cultural level, higher infant weight at delivery and at 6 months of life, and less prevalence of exclusive breastfeeding; all of them nutritional risk factors in the short and long term.