The nutritional consequences of pregnancy sickness: A critique of a hypothesis

The purpose of this paper is to assess Profet's (1992) and others' hypothesis that nausea and vomiting in pregnancy (NVP) is adaptive. A number of studies have found an association between NVP and a decreased risk for early fetal loss (<20 weeks). It is assumed that the adaptive benefits of improved survivorship associated with NVP outweigh the minimal nutritional consequences. However, in populations that experience marginal levels of nutrition, NVP may have important nutritional consequences. To test these potential consequences, a study on NVP, nutritional status, and pregnancy outcome was conducted among Turkana pastoralists, who experience seasonal and chronic nutritional stress. Interviews and anthropometric assessments were conducted on 68 pregnant Turkana women of Kenya during a 1993-1994 field season. The results from the case study suggest that women who experience NVP do encounter nutritional consequences in the later stages of pregnancy and are more likely to experience poor pregnancy outcomes. These results suggest that NVP may not be adaptive in all environmental settings, particularly among marginally nourished populations.