title: Firstborn offspring sex ratio is skewed towards female offspring in anesthesia care providers: A questionnaire-based nationwide study from United States.
abstract: BACKGROUND
  A parental occupation such as anesthesia care provider can involve exposure of the parent to various chemicals in the work environment and has been correlated to skewed offspring sex ratios.
  
  
  OBJECTIVE
  The objective was to conduct a nation-wide survey to observe (a) whether firstborn offspring sex ratio (OSR) in anesthesia providers is skewed towards increased female offspring, and (b) to identify potential factors influencing firstborn OSR, particularly those relating to the peri-conceptional practice of inhalational anesthesia induction among anesthesia providers.
  
  
  METHODS
  After institutional review board approval, a questionnaire was uploaded on SurveyMonkey and sent to anesthesia providers through their program coordinators in United States (US) to complete the survey.
  
  
  RESULTS
  The current US national total-population sex ratio is 0.97 male (s)/female with an at-birth sex ratio of 1.05 male (s)/female; comparatively, the results from anesthesia providers' survey respondents (n = 314) were a total OSR of 0.93 male (s)/female (P = 0.61) with firstborn OSR 0.82 male (s)/female (a 6% increase in female offspring; P = 0.03), respectively. The only significant peri-conceptional factor related to anesthesia providers' firstborn OSR's skew was inhalational induction practice by anesthesia care provider favoring female offspring (P < 0.01).
  
  
  CONCLUSIONS
  Based on the results of this limited survey, it can be concluded that anesthesia care providers who practice inhalation induction of anesthesia during the peri-conceptional period are significantly more likely to have firstborn female offspring.
authors.affiliation: Department of Anesthesiology, Wayne State University/Detroit Medical Center, Detroit, MI 48201, United States.
authors.forename: Deepak
authors.initials: D
authors.lastname: Gupta
authors.forename: Edward
authors.initials: E
authors.lastname: Kaminski
authors.forename: George
authors.initials: G
authors.lastname: McKelvey
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
keywords: Anesthesia care providers; inhalational induction of anesthesia; offspring sex ratio; parental occupation; peri-conceptional factors