Hyperemesis gravidarum and long-term mortality: a population-based cohort study.

OBJECTIVE: To investigate whether exposure to hyperemesis gravidarum (HG) is associated with increased maternal long-term mortality. DESIGN: Population-based cohort study. SETTING: Medical Birth Registry of Norway (1967-2002) linked to the Cause of Death Registry. POPULATION: Women in Norway with singleton births in the period 1967-2002, with and without HG. Women were followed until 2009 or death. METHODS: Cox proportional hazard regression model was applied to estimate hazard ratios (HRs) with 95% confidence interval (CI). MAIN OUTCOME MEASURES: The primary outcome was all-cause mortality during follow up. Secondary outcomes were cause-specific mortality (cardiovascular mortality, deaths due to cancer, external causes or mental and behavioural disorders). RESULTS: Of 999 161 women with singleton births, 13 397 (1.3%) experienced HG. During a median follow up of 26 years (25 902 036 person-years), 43 470 women died (4.4%). Women exposed to HG had a lower risk of long-term all-cause mortality compared with women without HG (crude HR 0.82; 95% CI 0.75-0.90). When adjusting for confounders, this reduction was no longer significant (adjusted HR 0.92; 95% CI 0.84-1.01). Women exposed to HG had a similar risk of cardiovascular death as women not exposed (adjusted HR 1.04; 95% CI 0.83-1.29), but a lower long-term risk of death from cancer (adjusted HR 0.86; 95% CI 0.75-0.98). CONCLUSION: In this large population-based cohort study, HG was not associated with an increased risk of long-term all-cause mortality. Women exposed to HG had no increase in mortality due to cardiovascular disease, but had a reduced risk of death from cancer. TWEETABLE ABSTRACT: Population-based cohort study: Hyperemesis was not associated with an increased risk of long-term mortality.

Hyperemesis gravidarum and birth outcomes-a population-based cohort study of 2.2 million births in the Norwegian Birth Registry.

OBJECTIVE: To study associations between hyperemesis gravidarum (HG) and birth outcomes. DESIGN: Population-based cohort study. SETTING: Norway. SAMPLE: Singleton births in the Norwegian Birth Registry, 1967-2009 (n = 2 270 363). METHODS: Multiple logistic regression was applied to study associations between HG and dichotomous outcomes; multiple linear regression to study associations between HG, birthweight and gestational length. Generalised estimating equations were applied to obtain valid standard errors. Sub-analysis on data with available information on smoking was conducted (1999-2009). MAIN OUTCOME MEASURES: Small and large for gestational age (SGA/LGA), Apgar score after 5 minutes, very preterm and preterm birth (VPTB/PTB), perinatal death, stillbirth, neonatal death, birthweight and gestational length. RESULTS: No associations between HG and adverse pregnancy outcomes were observed in crude analyses, except for VPTB (odds ratio [OR] 0.79, 95% CI 0.67-0.93). In adjusted analysis, HG was associated with perinatal death (OR 1.27, 95% CI 1.08-1.48). Inverse associations were observed between HG and VPTB (OR 0.80, 95% CI 0.68-0.94) and LGA (OR 0.95, 95% CI 0.90-0.99). Sub-analyses showed no associations between HG and perinatal death (OR 1.29, 95% CI 0.91-1.83). The inverse associations between HG, VPTB and LGA were strengthened (OR 0.66, 95% CI, 0.48-0.91 and OR 0.86, 95% CI 0.79-0.93, respectively). Exposed babies had reduced birthweight and gestational length compared with unexposed, adjusted difference - 21.4 g and - 0.5 days, respectively. Adjustment for smoking slightly strengthened the impact of HG on birthweight. CONCLUSIONS: Inverse associations for HG and VPTB and LGA were observed. HG was associated with slight reductions in birthweight and gestational age.

Nausea and vomiting in pregnancy: associations with maternal gestational diet and lifestyle factors in the Norwegian Mother and Child Cohort Study.

OBJECTIVE: To investigate primarily the dietary intake, as well as demographics and selected lifestyle factors, of women experiencing nausea and vomiting in pregnancy, nausea only, or women who are symptom free. DESIGN: Prospective cohort study. SETTING: The Norwegian Mother and Child Cohort Study, a population-based pregnancy cohort. SAMPLE: Analyses were based on 51 675 Norwegian pregnancies. METHODS: Dietary intake was assessed by a self-reported food frequency questionnaire answered in the first trimester of pregnancy, as were data regarding nausea and vomiting. Chi-squared tests, one-way analysis of variance, and multiple linear regression were used. MAIN OUTCOME MEASURES: Nausea and vomiting in pregnancy (NVP), gestational weight gain (GWG), and dietary intake. RESULTS: We found that 17 070 (33%) women experienced NVP, 20 371 (39%) experienced only nausea, and 14 234 (28%) were symptom free. Women with NVP were younger and heavier at pregnancy onset, with the lowest GWG and highest energy intake during pregnancy, primarily from carbohydrates and added sugars, compared with the other groups (P < 0.001). In multiple linear regression analysis of GWG and group adjusted for body mass index (BMI), gestational length, smoking during pregnancy, and energy intake, a significant interaction was found between BMI and group (P < 0.001). A significant effect of group (P < 0.001) was found in all BMI strata, except among underweight women (P = 0.65). CONCLUSIONS: Our study suggests that women with NVP are characterised by high intakes of carbohydrates and added sugar, primarily from sugar-containing soft drinks. Whether higher intakes of carbohydrates are a response aimed to alleviate symptoms, or are actually provoking the condition, is not known.