Excessive accumulation of fat in women of childbearing age is a concern, since obesity is an important cause of morbidity and mortality. Deposition of fat during pregnancy, which is not metabolized during lactation, may contribute. However, the individual effects of age and gravidity on fat accumulation have not been disentangled. Based on multiple linear regression analysis of anthropometric data from 1113 pregnant women from Zimbabwe, we found evidence to suggest that fat deposition is an effect of age rather than gravidity that is precipitated by the first pregnancy.