ABSTRACT
To examine the outcome of gestational blood pressure and birth weight in women with normal pre-pregnancy BMI (18.5-25 kg/m2) who are at the lower and upper limits of this range, i.e., slightly underweight or slightly overweight. Overall, 2,038 Japanese women with low -risk who had delivered during January 2014-December 2016 were classified according to their pre-pregnancy BMI: underweight (< 18.5 kg/m2), slightly underweight (18.5≤BMI<21 kg/m2), normal (21≤BMI<23 kg/m2), slightly overweight (23≤BMI<25 kg/m2) and overweight (≤ 25 kg/m2). Their blood pressure during each trimester and birth weight was evaluated. The slightly overweight group showed a significantly higher blood pressure than the underweight and slightly underweight groups. Birth weight was lower in the slightly underweight than in the slightly overweight group (p<0.01). The incidence rate of "heavy for dates" (HFD) infants was significantly higher in the slightly overweight and overweight groups than in the other groups (p<0.05 and p<0.01, respectively). Weight gain of < 7 kg significantly increased the rate of "light for dates" (LFD) infants, while a weight gain of ≥13 kg significantly increased the rate of HFD infants (p<0.05 and p<0.01, respectively). Blood pressure during pregnancy was ssociated with pre-pregnancy BMI. The birth weight of infants of low-risk pregnant women is affected by both pre-pregnancy BMI and gestational weight gain.
