title: Number of women requiring care at a tertiary hospital equipped with a neonatal intensive care unit at night in an area with a population of 2 million.
abstract: OBJECTIVE
  Women with imminent premature labor (IPL) are transported to a tertiary hospital equipped with neonatal intensive care unit (NICU) even during the night. However, there have been no extensive studies of the occurrence rate of night IPL. The aim of this study was to determine the occurrence rate of night IPL in an area with a population of 2 million.
  
  
  METHODS
  A retrospective analysis was conducted using data collected by the Sapporo Obstetric System for Emergency Patients launched in October 2008, in which women, physicians, and ambulance staff who sought appropriate obstetric/gynecological facilities available in the night (19.00-06.00 hours) were informed of candidate hospitals by coordinators through telephone consultation. This system covered the Sapporo area, which has a population of 2,000,000 and 17,000 births annually. Approximately 14% and 86% of women received antenatal care at six and 35 obstetric facilities with and without NICU, respectively, in this area. Night IPL was defined as a threatened premature labor and transport to one of six tertiary hospitals with NICU between 19.00 and 06.00 hours the next morning.
  
  
  RESULTS
  During a 4-year period from 1 October 2008 to 30 September 2012, the Sapporo Obstetric System for Emergency Patients received 158 ± 23 (mean ± standard deviation) monthly telephone consultations (range 114-218 per month). The monthly number of patients with night IPL was 3.0 ± 2.2 (range 0-9 per month).
  
  
  CONCLUSIONS
  The monthly number of cases of night IPL was around three among women who received antenatal care at obstetrics facilities without NICU in an area with a population of 2,000,000.
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Cho
authors.forename: Mamoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.forename: Rina
authors.initials: R
authors.lastname: Akaishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D005260:Female; D006801:Humans; D007363:Intensive Care Units, Neonatal; D007564:Japan; D009551:Night Care / Q000706:statistics & numerical data*; D011247:Pregnancy; D012189:Retrospective Studies; D062606:Tertiary Care Centers / Q000706:statistics & numerical data*; D014187:Transportation of Patients / Q000706:statistics & numerical data*
keywords: emergency; maternal transport; neonatal intensive care unit; premature labor; regionalization