Patterns of nausea, vomiting, aversions, and cravings during pregnancy on Pemba Island, Zanzibar, Tanzania.

The function(s) of nausea and vomiting in pregnancy (NVP) and its accompanying aversions and cravings remain unresolved. Neither of the two major adaptive hypotheses, "maternal/embryo protection" and "placental growth," have been tested using data from a low-income country. We examined NVP in a cross-sectional study of 427 pregnant women. The prevalence of NVP was comparable to resource-rich contexts: 69.6%, 55.5%, 70.0%, and 64.9% reported NVP, gustatory aversions, olfactory aversions, and cravings, respectively. The prevalence of all phenomena was highest in the first trimester. The timing and characteristics of NVP, aversions, and cravings were most consistent with the protection hypothesis.