What weight gain should a woman with a prepregnancy BMI of 21 kg/m2 expect during her pregnancy?

A woman with a prepregnancy BMI of 21 kg/m² falls within the normal weight range. According to established guidelines from organizations like the Institute of Medicine, women with a normal BMI are generally advised to gain a total of 25 to 35 pounds throughout the course of their pregnancy.

The recommendation for total weight gain is important because it supports healthy fetal development and prepares the mother’s body for breastfeeding and recovery postpartum. The suggestion of 30 pounds aligns well with the middle range of the total weight gain recommended for someone with a normal BMI and provides a good target for healthy weight management during pregnancy.

Other choices present different weight gain recommendations that either fall short of or exceed these guidelines or suggest a weight gain strategy that is not consistent with typical recommendations during pregnancy phases. Therefore, option B accurately reflects the expected weight gain for a woman with a prepregnancy BMI of 21 kg/m².