title: Nationwide data confirms absence of 'July phenomenon' in obstetrics: it's safe to deliver in July.
abstract: OBJECTIVE
  To determine whether operator-dependent obstetric complications occur at higher rates in July at teaching hospitals using a large, nationwide sample of deliveries.
  
  
  METHODS
  Data for this study were obtained from an administrative dataset, the Nationwide Inpatient Sample, for the years 1998 to 2002. Singleton deliveries and singleton livebirth admissions among Medicaid patients at teaching hospitals with OB/GYN residents working on the Labor and Delivery ward were identified. Outcomes for various complications for these patients in the month of July were compared to those occurring in the months from August to June.
  
  
  RESULTS
  The 26,546 women in our cohort who delivered in July were compared to the 272,584 women delivering during August to June. There were no statistically significant differences in the rates of cesarean delivery, urethral/bladder injury, third or fourth degree lacerations, wound complications, postpartum hemorrhage, transfusion, shoulder dystocia, chorioamnionitis or anesthesia-related complications. The 26,175 singleton livebirth admissions in July were compared to 266,158 such admissions in August to June. There were no statistically significant differences in the rates of brachial plexus injury (0.2 vs 0.2%, P=0.824) or birth asphyxia (0.1 vs 0.1%, P=0.643).
  
  
  CONCLUSIONS
  This study shows no increased rate of operator-dependent complications of delivery at teaching hospitals nationwide in the month of July.
authors.affiliation: College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Ford
authors.forename: B T
authors.initials: BT
authors.lastname: Bateman
authors.forename: L L
authors.initials: LL
authors.lastname: Simpson
authors.forename: R B
authors.initials: RB
authors.lastname: Ratan
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D036861:Delivery, Obstetric / Q000009:adverse effects / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007396:Internship and Residency / Q000706:statistics & numerical data*; D009774:Obstetrics / Q000193:education*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D012449:Safety; D012621:Seasons