The effect of leptin concentrations and other maternal characteristics on gestational weight gain is different according to pre-gestational BMI: results from a prospective cohort.

OBJECTIVE: To evaluate the effect of leptin and other selected variables on gestational weight gain (GWG) according to pre-gestational body mass index (BMI).

DESIGN: Prospective cohort.

SETTING: Public Health Center, Rio de Janeiro, Brazil.

SAMPLE: Two hundred and twenty-eight pregnant women.

METHODS: Women were followed at the 5-13, 20-26 and 30-36th gestational weeks. The effects of independent variables on GWG in normal weight (BMI 18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9 kg/m(2) ) and obese (BMI ≥ 30.0 kg/m(2) ) women were assessed using longitudinal linear mixed-effects models.

MAIN OUTCOME MEASURE: Maternal body weight (kg) throughout pregnancy.

RESULTS: Leptin concentrations were associated with GWG in normal weight (β = 0.048, P < 0.001) and overweight (β = 0.023, P = 0.048) women, but not in obese ones (β = 0.011, P = 0.308). Additionally, the number of hours slept per night decreased the effect of leptin on GWG in OW women (β = -0.013, P = 0.002). The effect of other maternal characteristics on GWG was different depending on the BMI category.

CONCLUSIONS: Leptin concentrations were positively associated with GWG in normal weight and overweight women, but not in obese ones. Maternal height was associated with GWG in all BMI categories, but other variables such as sleep duration, QUICKI values, HDL-c, smoking habit and marital status presented differential effects according to BMI. We encourage further studies to investigate the association between leptin and gestational weight gain, taking into account the pre-pregnancy weight and sleep duration, in order to compare and confirm our results.

TWEETABLE ABSTRACT: Leptin is associated with weight gain in normal weight and overweight pregnant women, but not in obese ones.