title: Maternal and perinatal outcomes of pregnancies delivered at 23 weeks' gestation.
abstract: OBJECTIVE
  To evaluate the maternal and perinatal outcomes of pregnancies delivered at 23+0 to 23+6 weeks' gestation.
  
  
  METHODS
  This prospective cohort study included women in the Canadian Perinatal Network who were admitted to one of 16 Canadian tertiary perinatal units between August 1, 2005, and March 31, 2011, and who delivered at 23+0 to 23+6 weeks' gestation. Women were included in the network if they were admitted with spontaneous preterm labour with contractions, a short cervix without contractions, prolapsing membranes with membranes at or beyond the external os or a dilated cervix, preterm premature rupture of membranes, intrauterine growth restriction, gestational hypertension, or antepartum hemorrhage. Maternal outcomes included Caesarean section, placental abruption, and serious complication. Perinatal outcomes were mortality and serious morbidity.
  
  
  RESULTS
  A total of 248 women and 287 infants were included in the study. The rate of Caesarean section was 10.5% (26/248) and 40.3% of women (100/248) had a serious complication, the most common being chorioamnionitis (38.6%), followed by blood transfusion (4.5%). Of infants with known outcomes, perinatal mortality was 89.9% (223/248) (stillbirth 23.3% [67/287] and neonatal death 62.9% [156/248]). Of live born neonates with known outcomes (n = 181), 38.1% (69/181) were admitted to NICU. Of those admitted to NICU, neonatal death occurred in 63.8% (44/69). Among survivors at discharge, the rate of severe brain injury was 44.0% (11/25), of retinopathy of prematurity 58.3% (14/24), and of any serious neonatal morbidity 100% (25/25). Two subgroup analyses were performed: in one, antepartum stillbirths were excluded, and in the other only centres that indicated they offered fetal monitoring at 23 weeks' gestation were included and antepartum stillbirths were excluded. In each of these, perinatal outcomes similar to the overall group were found.
  
  
  CONCLUSIONS
  Pregnant women delivering at 23 weeks' gestation are at risk of morbidity. Their infants have high rates of serious morbidity and mortality. Further research is needed to identify strategies and forms of management that not only increase perinatal survival but also reduce morbidities in these extremely low gestational age infants and reduce maternal morbidity.
authors.affiliation: Department of Obstetrics and Gynecology, Eastern Health, Memorial University of Newfoundland, St. John's NL.
authors.forename: Joan M G
authors.initials: JM
authors.lastname: Crane
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver BC; Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC; Department of School of Population and Public Health, University of British Columbia, Vancouver BC; Child and Family Research Institute, University of British Columbia, Vancouver BC.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Magee
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC.
authors.forename: Tang
authors.initials: T
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, University of British Columbia, Vancouver BC.
authors.forename: Anne
authors.initials: A
authors.lastname: Synnes
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC; Department of School of Population and Public Health, University of British Columbia, Vancouver BC; Child and Family Research Institute, University of British Columbia, Vancouver BC.
authors.forename: Peter
authors.initials: P
authors.lastname: von Dadelszen
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC.
authors.forename: Leanne
authors.initials: L
authors.lastname: Dahlgren
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC; Department of School of Population and Public Health, University of British Columbia, Vancouver BC.
authors.forename: Dane A
authors.initials: DA
authors.lastname: De Silva
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver BC.
authors.forename: Robert
authors.initials: R
authors.lastname: Liston
mesh_terms: D000328:Adult; D001927:Brain Diseases / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D002585:Cesarean Section / Q000706:statistics & numerical data; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000453:epidemiology; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D009017:Morbidity; D066087:Perinatal Death; D054238:Perinatal Mortality; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000401:mortality / Q000503:physiopathology; D011446:Prospective Studies; D012178:Retinopathy of Prematurity / Q000453:epidemiology
keywords: extreme preterm birth; maternal; perinatal; periviable birth