title: Long QT syndrome and pregnancy.
abstract: OBJECTIVE
  This study was designed to investigate the clinical course of women with long QT syndrome (LQTS) throughout their potential childbearing years.
  
  
  BACKGROUND
  Only limited data exist regarding the risks associated with pregnancy in women with LQTS.
  
  
  METHODS
  The risk of experiencing an adverse cardiac event, including syncope, aborted cardiac arrest, and sudden death, during and after pregnancy was analyzed for women who had their first birth from 1980 to 2003 (n = 391). Time-dependent Kaplan-Meier and Cox proportional hazard methods were used to evaluate the risk of cardiac events during different peripartum periods.
  
  
  RESULTS
  Compared with a time period before a woman's first conception, the pregnancy time was associated with a reduced risk of cardiac events (hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.10 to 0.76, p = 0.01), whereas the 9-month postpartum time had an increased risk (HR 2.7, 95% CI 1.8 to 4.3, p < 0.001). After the 9-month postpartum period, the risk was similar to the period before the first conception (HR 0.91, 95% CI 0.55 to 1.5, p = 0.70). Genotype analysis (n = 153) showed that women with the LQT2 genotype were more likely to experience a cardiac event than women with the LQT1 or LQT3 genotype. The cardiac event risk during the high-risk postpartum period was reduced among women using beta-blocker therapy (HR 0.34, 95% CI 0.14 to 0.84, p = 0.02).
  
  
  CONCLUSIONS
  Women with LQTS have a reduced risk for cardiac events during pregnancy, but an increased risk during the 9-month postpartum period, especially among women with the LQT2 genotype. Beta-blockers were associated with a reduction in cardiac events during the high-risk postpartum time period.
authors.affiliation: Cardiology Division of the Department of Medicine, University of Rochester Medical Center, Rochester, New York 14642, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Seth
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.forename: Mark L
authors.initials: ML
authors.lastname: Andrews
authors.forename: Ming
authors.initials: M
authors.lastname: Qi
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Robinson
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ackerman
authors.forename: Jesaia
authors.initials: J
authors.lastname: Benhorin
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kaufman
authors.forename: Emanuela H
authors.initials: EH
authors.lastname: Locati
authors.forename: Carlo
authors.initials: C
authors.lastname: Napolitano
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Priori
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Schwartz
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Towbin
authors.forename: G Michael
authors.initials: GM
authors.lastname: Vincent
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000328:Adult; D015331:Cohort Studies; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000209:etiology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006323:Heart Arrest / Q000401:mortality; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000401:mortality; D010298:Parity; D049590:Postpartum Period; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000175:diagnosis* / Q000401:mortality; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D011336:Probability; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment