title: Risk factors for hyperemesis gravidarum requiring hospital admission during pregnancy.
abstract: OBJECTIVE
  To identify risk factors for hyperemesis requiring hospital admission during pregnancy.
  
  
  METHODS
  Data from a population-based cohort of all deliveries in Nova Scotia, Canada between 1988 and 2002 were obtained from the Nova Scotia Atlee Perinatal Database. Women with 1 or more antepartum admissions for hyperemesis were compared with women with no admissions for hyperemesis. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using logistic regression and used to determine a set of independent risk factors for hyperemesis.
  
  
  RESULTS
  The overall rate of admission for hyperemesis was 0.8% (n = 1,301) among 157,922 deliveries. In the adjusted analysis, hyperthyroid disorders (RR 4.5, 95% CI 1.8-11.1), psychiatric illness (RR 4.1, 95% CI 3.0-5.7), previous molar pregnancy (RR 3.3, 95% CI 1.6-6.8), preexisting diabetes (RR 2.6, 95% CI 1.5-4.7), gastrointestinal disorders (RR 2.5, 95% CI 1.8-3.6), and asthma (RR 1.5, 95% CI 1.2-1.9) were all statistically significant risk factors for hyperemesis, whereas maternal smoking and maternal age older than 30 were associated with decreased risk. Compared with singleton male pregnancies, singleton female pregnancies, pregnancies with multiple male fetuses, and male and female combinations were associated with statistically significant increased risk of hyperemesis.
  
  
  CONCLUSIONS
  Although hospitalization for hyperemesis occurs in less than 1% of pregnant women, this translates to a large number of hospital admissions. The factors associated with hyperemesis are primarily medical and fetal factors that are not easily modifiable, but identification of these factors may be useful in determining those women at high risk for developing hyperemesis.
  
  
  METHODS
  II-2.
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Obstetrics and Gynaecology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Deshayne B
authors.initials: DB
authors.lastname: Fell
authors.forename: Linda
authors.initials: L
authors.lastname: Dodds
authors.forename: K S
authors.initials: KS
authors.lastname: Joseph
authors.forename: Victoria M
authors.initials: VM
authors.lastname: Allen
authors.forename: Blair
authors.initials: B
authors.lastname: Butler
mesh_terms: D000328:Adult; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006939:Hyperemesis Gravidarum / Q000453:epidemiology* / Q000628:therapy*; D008875:Middle Aged; D011247:Pregnancy; D012307:Risk Factors; D012720:Severity of Illness Index