title: High prevalence of severe nausea and vomiting of pregnancy and hyperemesis gravidarum among relatives of affected individuals.
abstract: OBJECTIVE
  The goal of this study was to determine the prevalence of severe nausea and vomiting of pregnancy/hyperemesis gravidarum among relatives of affected individuals.
  
  
  METHODS
  Family history data were obtained on 1224 self-reported cases of hyperemesis gravidarum. Cases completed an online survey administered by the Hyperemesis Education and Research Foundation between 2003 and 2006.
  
  
  RESULTS
  Approximately 28% of cases reported their mother had severe nausea and vomiting or hyperemesis gravidarum while pregnant with them. Of the 721 sisters with a pregnancy history, 137 (19%) had hyperemesis gravidarum. Among the most severe cases, those requiring total parenteral nutrition or nasogastric feeding tube, the proportion of affected sisters was even higher, 49/198 (25%). Nine percent of cases reported having at least two affected relatives including sister(s), mother, grandmother, daughters, aunt(s), and cousin(s).
  
  
  CONCLUSIONS
  There is a high prevalence of severe nausea and vomiting of pregnancy/hyperemesis gravidarum among relatives of hyperemesis gravidarum cases in this study population. Because the incidence of hyperemesis gravidarum is most commonly reported to be 0.5%, this study provides strong but preliminary evidence for a genetic component to extreme nausea and vomiting of pregnancy.
authors.affiliation: Keck School of Medicine, University of Southern California, Department of Obstetrics and Gynecology, Los Angeles, USA. mfejzo@mednet.ucla.edu
authors.forename: Marlena S
authors.initials: MS
authors.lastname: Fejzo
authors.forename: Sue Ann
authors.initials: SA
authors.lastname: Ingles
authors.forename: Melissa
authors.initials: M
authors.lastname: Wilson
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Kimber
authors.initials: K
authors.lastname: MacGibbon
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Goodwin