title: Fetal Sex and the Natural History of Maternal Risk of Diabetes During and After Pregnancy.
abstract: BACKGROUND
  It has recently emerged that carrying a male fetus is associated with poorer maternal β-cell function in pregnancy and an increased risk of gestational diabetes mellitus (GDM). β-cell dysfunction is the central pathophysiologic defect underlying both GDM and subsequent postpartum progression to type 2 diabetes mellitus (T2DM).
  
  
  OBJECTIVE
  This was a retrospective cohort study that aimed to determine whether fetal sex influences the natural history of maternal risk of diabetes after delivery and in a subsequent pregnancy.
  
  
  METHODS
  The study was conducted using population-based administrative databases in Ontario, Canada.
  
  
  METHODS
  All women with a singleton live-birth first pregnancy between April 2000 and March 2010 (n = 642 987) were included.
  
  
  METHODS
  Fetal sex was the exposure of interest (313 280 delivered a girl; 329 707 delivered a boy).
  
  
  METHODS
  Development of T2DM or a second pregnancy were the main outcome measures. Glucose tolerance in each pregnancy was classified as either GDM or non-GDM.
  
  
  RESULTS
  The population was followed for a median of 3.8 years. Carrying a boy yielded a higher risk of GDM in both the first pregnancy (odds ratio [OR] =1.03; 95% confidence interval [CI], 1.0002-1.054) and second pregnancy (OR =1.04, 95% CI, 1.01-1.08). For women with GDM in the first pregnancy, the likelihood of developing T2DM before a second pregnancy was higher if they delivered a girl (OR = 1.07; 95% CI, 1.01-1.12). Recurrence of GDM was not affected by fetal sex (P = .7). However, among women with a non-GDM first pregnancy while carrying a girl, having a boy in their second pregnancy predicted an increased risk of GDM (OR = 1.07, 95% CI, 1.01-1.14).
  
  
  CONCLUSIONS
  Fetal sex is a previously unrecognized factor that is associated with maternal diabetic risk both after delivery and in a subsequent pregnancy.
authors.affiliation: Lunenfeld-Tanenbaum Research Institute (R.R.), Mt Sinai Hospital, Toronto, Canada M4G 1X5; Leadership Sinai Centre for Diabetes (R.R.), Mt Sinai Hospital, Toronto, Canada M4G 1X5; Division of Endocrinology, University of Toronto (R.R., B.R.S.), Toronto, Canada M4G 2C4; Department of Medicine (B.R.S.), Sunnybrook Health Sciences Centre, Toronto, Canada M4N 3M5; and Institute for Clinical and Evaluative Sciences (B.R.S.), Toronto, Canada M4N 3M5.
authors.forename: Ravi
authors.initials: R
authors.lastname: Retnakaran
authors.affiliation: Lunenfeld-Tanenbaum Research Institute (R.R.), Mt Sinai Hospital, Toronto, Canada M4G 1X5; Leadership Sinai Centre for Diabetes (R.R.), Mt Sinai Hospital, Toronto, Canada M4G 1X5; Division of Endocrinology, University of Toronto (R.R., B.R.S.), Toronto, Canada M4G 2C4; Department of Medicine (B.R.S.), Sunnybrook Health Sciences Centre, Toronto, Canada M4N 3M5; and Institute for Clinical and Evaluative Sciences (B.R.S.), Toronto, Canada M4N 3M5.
authors.forename: Baiju R
authors.initials: BR
authors.lastname: Shah
mesh_terms: D002170:Canada / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology*; D016640:Diabetes, Gestational / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005333:Fetus / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D050417:Insulin-Secreting Cells / Q000502:physiology; D008297:Male; D049590:Postpartum Period; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors