多达 75% 的妊娠女性会出现妊娠期恶心呕吐 (NVP)。[2]Gadsby R, Barnie-Adshead AM, Jagger C. A prospective study of nausea and vomiting during pregnancy. Br J Gen Pract. 1993;43:245-248.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1372422/http://www.ncbi.nlm.nih.gov/pubmed/8373648?tool=bestpractice.com但是部分数据表明，在不同的社会经济群体中，发生率也有所不同。相比城市女性，乡村女性更少出现 NVP。[3]Semmens JP. Female sexuality and life situations. An etiologic psycho-socio-sexual profile of weight gain and nausea and vomiting in pregnancy. Obstet Gynecol. 1971;38:555-563.http://www.ncbi.nlm.nih.gov/pubmed/4938580?tool=bestpractice.com相比家庭妇女，白人职业女性具有较低的 NVP 发生率。[4]Weigel MM, Weigel RM. The association of reproductive history, demographic factors, and alcohol and tobacco consumption with the risk of developing nausea and vomiting in early pregnancy. Am J Epidemiol. 1988;127:562-570.http://www.ncbi.nlm.nih.gov/pubmed/3341360?tool=bestpractice.com35岁以上有不孕病史的妇女发生率也较低。[4]Weigel MM, Weigel RM. The association of reproductive history, demographic factors, and alcohol and tobacco consumption with the risk of developing nausea and vomiting in early pregnancy. Am J Epidemiol. 1988;127:562-570.http://www.ncbi.nlm.nih.gov/pubmed/3341360?tool=bestpractice.com
每 200 名妊娠女性中有一人发生妊娠剧吐，这是 NVP 的一种严重形式。[5]Fairweather DV. Nausea and vomiting in pregnancy. Am J Obstet Gynecol. 1968;102:135-175.http://www.ncbi.nlm.nih.gov/pubmed/4877794?tool=bestpractice.com多次妊娠、妊娠滋养细胞疾病、三倍体、21-三体和胎儿水肿等可导致发生率升高。[1]Goodwin TM. Hyperemesis gravidarum. Clin Obstet Gynecol. 1998;41:597-605.http://www.ncbi.nlm.nih.gov/pubmed/9742356?tool=bestpractice.com
