title: Effect of chronic hypertension on assisted pregnancy outcomes: a population-based study in Ontario, Canada.
abstract: OBJECTIVE
  To evaluate maternal and neonatal outcomes in women with chronic hypertension who conceive using assisted reproductive technologies (ART).
  
  
  METHODS
  Population-based retrospective cohort study.
  
  
  METHODS
  Obstetric hospitals.
  
  
  METHODS
  Singleton pregnancies of at least 20 weeks' gestational age to women 18 years and older who delivered a live or stillborn infant between April 1, 2006, and March 31, 2012, categorized as exposed based on a diagnosis of chronic hypertension in the mother predating the index pregnancy.
  
  
  METHODS
  Medically assisted pregnancy including in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI), intrauterine insemination, and ovulation induction.
  
  
  METHODS
  
  
  
  METHODS
  placental-mediated complications of pregnancy (preeclampsia/eclampsia, stillbirth, fetal growth restriction/low birthweight [<10th percentile], or clinically significant placental abruption); secondary outcomes: cesarean delivery (planned/unplanned), prematurity (<37 or <32 weeks), and neonatal death.
  
  
  RESULTS
  Our cohort included 807,765 singleton pregnancies. We used log binomial regression to compute the adjusted relative risks of the various outcomes in women with hypertension as compared with healthy women in ART and unassisted pregnancies. When we tested an interaction term between hypertension and ART in multivariate models, women with ART pregnancies were at higher risk of placental-mediated complications than were those with unassisted pregnancies (adjusted risk ratio 1.48; 95% confidence interval, 1.35, 1.56). The risk was even greater in hypertensive women who used ART (adjusted risk ratio 6.77; 95% confidence interval, 4.72, 9.72). Our findings persisted when assessing IVF only and when evaluating nulliparas.
  
  
  CONCLUSIONS
  Hypertension is more frequent in ART-treated women. Hypertension increases the risk of placental complications, which appear to be compounded in ART versus unassisted pregnancies.
authors.affiliation: McGill University Health Centre, McGill University, Montreal, Quebec, Canada. Electronic address: natalie.dayan@mcgill.ca.
authors.forename: Natalie
authors.initials: N
authors.lastname: Dayan
authors.affiliation: School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada; BORN Ontario, CHEO Research Institute, Ottawa, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lanes
authors.affiliation: BORN Ontario, CHEO Research Institute, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, Center for Practice-Changing Research, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Walker
authors.affiliation: LifeQuest Centre for Reproductive Medicine, Toronto, Ontario, Canada.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Spitzer
authors.affiliation: LifeQuest Centre for Reproductive Medicine, Toronto, Ontario, Canada; Department of Medicine and Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Carl A
authors.initials: CA
authors.lastname: Laskin
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology*; D007231:Infant, Newborn; D009864:Ontario / Q000453:epidemiology; D011159:Population Surveillance / Q000379:methods; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000453:epidemiology*; D011256:Pregnancy Outcome / Q000453:epidemiology*; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects* / Q000639:trends; D012189:Retrospective Studies; D012307:Risk Factors
keywords: ART; hypertension; placental complications of pregnancy