One-Year Survival of Extremely Preterm Infants After Active Perinatal Care in Sweden
- The EXPRESS Group
- Authors/EXPRESS Group Members: Mats Blennow, MD, PhD, Department of Pediatrics, Karolinska University Hospital, Huddinge, and Department of Clinical Investigation, Intervention, & Technology, Karolinska Institutet, Stockholm, Sweden; Uwe Ewald, MD, PhD, Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden; Tomas Fritz, MD, Department of Obstetrics and Gynecology, Sahlgrenska University Hospital, Göteborg, Sweden; Per Åke Holmgren, MD, PhD, Department of Clinical Sciences, Obstetrics, and Gynecology, Umeå University, Umeå, Sweden; Annika Jeppsson, MD, PhD, Department of Obstetrics and Gynecology, Linköping University, Linköping, Sweden; Eva Lindberg, MD, Department of Pediatrics, Örebro University, Örebro, Sweden; Anita Lundqvist, PhD, Department of Health Sciences, Lund University, Lund, Sweden; Solveig Nordén Lindeberg, MD, PhD, Department of Obstetrics and Gynecology, Uppsala University; Elisabeth Olhager, MD, PhD, Department of Pediatrics, Linköping University; Ingrid Östlund, MD, PhD, Department of Obstetrics and Gynecology, Örebro University Hospital, Örebro; Marija Simic, MD, Department of Obstetrics and Gynecology, Karolinska University Hospital Solna, Stockholm; Gunnar Sjörs, MD, PhD, Department of Pediatrics, Uppsala University; Lennart Stigson, MD, Department of Pediatrics, Sahlgrenska University Hospital. Writing committee members: Vineta Fellman, MD, PhD, Department of Pediatrics, Clinical Sciences Lund, Lund University; Lena Hellström-Westas, MD, PhD, Department of Women's and Children's Health, Uppsala University; Mikael Norman, MD, PhD, Department of Pediatrics, Karolinska University Hospital, Huddinge and Department of Clinical Investigation, Intervention & Technology, Karolinska Institutet, Stockholm; Magnus Westgren, MD, PhD, Department of Obstetrics and Gynecology, Karolinska University Hospital Huddinge. Expert group members: Gerd Holmström, MD, PhD, Department of Ophthalmology, Uppsala University; Ricardo Laurini, MD, PhD, Department of Pathology, Nordland Hospital, Bodö, Norway; Karin Stjernqvist, PhD, Department of Psychology, Lund University. Steering group and writing committee members: Karin Källén, PhD, Centre of Reproductive Epidemiology, Lund University; Hugo Lagercrantz, MD, PhD, Department of Women and Child Health, Karolinska Institute, Stockholm, Astrid Lindgren Children's Hospital, Stockholm; Karel Maršál, MD, PhD, Department of Obstetrics and Gynecology, Clinical Sciences Lund, Lund University; Fredrik Serenius, MD, PhD, Department of Clinical Sciences, Pediatrics, Umeå University; Margareta Wennergren, MD, PhD, Department of Obstetrics and Gynecology, Sahlgrenska University Hospital. Steering group members: Tore Nilstun, PhD, Department of Medical Ethics, Lund University; Petra Otterblad Olausson, PhD, Centre of Epidemiology, The National Board of Health and Welfare, Stockholm; Bo Strömberg, MD, PhD, Department of Pediatrics, Uppsala University.
Abstract
Context Up-to-date information on infant survival after extremely preterm birth is needed for assessing perinatal care services, clinical guidelines, and parental counseling.
Objective To determine the 1-year survival in all infants born before 27 gestational weeks in Sweden during 2004-2007.
Design, Setting, and Patients Population-based prospective observational study of extremely preterm infants (707 live-born and 304 stillbirths) born to 887 mothers in 904 deliveries (102 multiple births) in all obstetric and neonatal units in Sweden from April 1, 2004, to March 31, 2007.
Main Outcome Measures Infant survival to 365 days and survival without major neonatal morbidity (intraventricular hemorrhage grade >2, retinopathy of prematurity stage >2, periventricular leukomalacia, necrotizing enterocolitis, severe bronchopulmonary dysplasia). Associations between perinatal interventions and survival.
Results The incidence of extreme prematurity was 3.3 per 1000 infants. Overall perinatal mortality was 45% (from 93% at 22 weeks to 24% at 26 weeks), with 30% stillbirths, including 6.5% intrapartum deaths. Of live-born infants, 91% were admitted to neonatal intensive care and 70% survived to 1 year of age (95% confidence interval [CI], 67%-73%). The Kaplan-Meier survival estimates for 22, 23, 24, 25, and 26 weeks were 9.8% (95% CI, 4%-23%), 53% (95% CI, 44%-63%), 67% (95% CI, 59%-75%), 82% (95% CI, 76%-87%), and 85% (95% CI, 81%-90%), respectively. Lower risk of infant death was associated with tocolytic treatment (adjusted for gestational age odds ratio [OR], 0.43; 95% CI, 0.36-0.52), antenatal corticosteroids (OR, 0.44; 95% CI, 0.24-0.81), surfactant treatment within 2 hours after birth (OR, 0.47; 95% CI, 0.32-0.71), and birth at a level III hospital (OR, 0.49; 95% CI, 0.32-0.75). Among 1-year survivors, 45% had no major neonatal morbidity.
Conclusion During 2004 to 2007, 1-year survival of infants born alive at 22 to 26 weeks of gestation in Sweden was 70% and ranged from 9.8% at 22 weeks to 85% at 26 weeks.
