The effect of pregnancy weight gain on later obesity.

OBJECTIVE

To determine whether weight increases permanently as a result of pregnancy and to explore the determinants of postpartum weight retention.

DATA SOURCES

Articles from the literature on obesity, parity, and gestational and postpartum weight changes were identified through a literature search.

METHODS OF STUDY SELECTION

Studies from the last decade that examined weight changes related to pregnancy or parity in developed countries were selected if they provided adequate information to allow useful comparisons to other studies.

DATA EXTRACTION AND SYNTHESIS

Average gestational and postpartum weight changes and their range of variation were noted. Studies emphasizing information related to weight change were used to identify alternative explanations for weight changes often credited to pregnancy. Explanations consistent with data from all of the different kinds of studies were developed by synthesis of the varied reports.

CONCLUSIONS

Aging is a major determinant of weight increases associated with parity in cross-sectional studies. Average weight increments are generally less than 1.5 kg (3 lb) during a single reproductive cycle (before pregnancy to 1 year postpartum), but obese women tend to have larger weight changes (both increases and decreases) than lower-weight women. Under-reporting of pre-pregnancy weight, particularly by overweight women, probably contributes to overestimation of weight gain during pregnancy and estimated retained weight. A small number of women increase weight greatly during a reproductive cycle. The studies do not prove that this is the result of the pregnancy per se. Some women gain weight postpartum, suggesting that life-style factors can be significant determinants of weight gain during a reproductive cycle. Preventive efforts targeted to the postpartum visit could be useful.