Association between women's perceived ideal gestational weight gain during pregnancy and pregnancy outcomes.

We aimed to clarify which beliefs motivate women to control their weight during pregnancy and how such values influence pregnancy outcomes. Using a questionnaire administered during mid- to late- pregnancy in a hospital-based prospective cohort study, we explored women's perceived ideal GWG and their reasons for having this ideal. Using multivariate regression, we evaluated the association between women's perceived ideal GWG and pregnancy outcomes. Among 1,691 normal and underweight women, the most common reason women thought avoiding excessive weight gain was important was "for ease of delivery and/or her health and well-being". 912 (54%) women wished to maintain their GWG below 12 kg, the upper limit recommended by the Japanese governmental guidelines, and had a lower actual GWG compared to those who had less stringent notions of GWG. Compared to women whose perceived ideal GWG was 12 kg, those who considered their perceived limit to be lower had infants with lower birthweight on average despite no significant reduction in cesarean delivery rate or post-partum body weight retention. Our findings suggest that women who believe they should limit their weight gain to an amount lower than the upper limit of current guidelines succeeded in gaining significantly less weight but received no additional benefit.