Gestational weight gain as predicted by pregestational body mass index and gestational age in Mexican women.

OBJECTIVE: To develop a reference pattern to evaluate gestational weight according to pregestational body mass index (BMI) and gestational age, using current longitudinal information from healthy pregnant women.

SUBJECTS AND METHODS: We followed 438 women with singleton pregnancies between weeks 16 and 36 of pregnancy Women were excluded if they developed pathologic conditions during gestation, delivered malformed or dead fetuses, or delivered babies with a birthweight of less than 2500 or more than 4200 g or with a gestational age of less than 37 or more than 41 weeks. Weight, biochemical indicators, and clinical indicators were recorded every 4 weeks throughout the pregnancy. Data were analyzed by sequential regressions.

RESULTS: Four equations for maternal predicted weight across categories of pregestational BMI (underweight, normal, overweight, and obese) and gestational ages were developed and synthesized in a table of reference values.

CONCLUSIONS: Optimal weight and weight gain during pregnancy can be estimated with our equations, which are corrected for pregestational BMI and gestational age.