Introduction: The pathogenesis and risk factors for hyperemesis gravidarum, excessive nausea and vomiting of pregnancy, are not adequately recognized. In our previous study, we found that women with a personal history of nausea in different situations and a family history of nausea and vomiting of pregnancy (NVP) were more likely to have severe NVP. The present study focuses on these themes in association with hyperemesis gravidarum in a hospital setting.

Material and methods: Women with hyperemesis gravidarum (n = 102) were recruited from among patients hospitalized due to hyperemesis gravidarum in Turku University Hospital, Finland. Our control group (Non-NVP group, n = 138) consisted of pregnant women with no NVP. Personal history of nausea in different situations was inquired about in relation to "motion sickness", "seasickness", "migraine", "other kind of headache", "after anesthesia", "during the use of contraception", and "other kinds of nausea". Relatives with NVP were divided into first-degree (mother and sisters) and second-degree (more distant) relatives.

Results: In univariate analysis, a personal history of motion sickness, seasickness, nausea related to migraine, nausea with other headache and nausea in other situations were associated with hyperemesis gravidarum. After adjusting for age, parity, pre-pregnancy body mass index, marital status, and smoking, motion sickness (adjusted odds ratio [aOR] 5.24, 95% confidence interval [CI] 2.67-10.31, p < 0.0001), seasickness (aOR 4.82, 95% CI 2.32-10.03, p < 0.0001), nausea related to migraine (aOR 3.00, 95% CI 1.58-5.70, p < 0.001), and nausea in other situations (aOR 2.65, 95% CI 1.13-6.20, p = 0.025) remained significant. In multivariable analysis with all history of nausea variables, motion sickness (OR 2.76, 95% CI 1.29-5.89, p = 0.009) and nausea related to migraine (OR 3.10, 95% CI 1.40-6.86, p = 0.005) were associated with hyperemesis gravidarum. Having any affected relative (OR 3.51, 95%CI 1.84-6.73, p = 0.0002), especially a first-degree relative (OR 3.06, 95% CI 1.62-5.79, p = 0.0006), was also associated with hyperemesis gravidarum. Adjustment did not change the results.

Conclusions: Women with a personal history of nausea or a family history of NVP are more likely to suffer from hyperemesis gravidarum. These results are beneficial to better identify and help women at risk for hyperemesis gravidarum.