Improved Survival Rates With Increased Neurodevelopmental Disability for Extremely Low Birth Weight Infants in the 1990s

Background. Advances in perinatal care have resulted in increased survival rates for extremely low birth weight children. We sought to examine the relative changes in rates of survival and neurodevelopmental impairment at 20 months of corrected age among 500- to 999-g birth weight infants born at our perinatal center during 2 periods, before and after the introduction of surfactant therapy in 1990. Methods. Four hundred ninety-six infants with birth weights of 500 to 999 g were born at our perinatal center during period I (1982–1989) (mean body weight: 762 g; mean gestational age: 25.8 weeks) and 682 during period II (1990–1998) (mean body weight: 756 g; mean gestational age: 25.5 weeks). Rates of death and survival with and without neurodevelopmental impairment at 20 months of corrected age for the 2 periods were compared with logistic regression analyses, with adjustment for gestational age. Results. Survival rates increased from 49% during period I to 67% during period II. Neonatal morbidity rates also increased during period II, including rates of sepsis (from 37% to 51%), periventricular leukomalacia (from 2% to 7%), and chronic lung disease, defined as oxygen dependence at 36 weeks of corrected age (from 32% to 43%). Rates of severe cranial ultrasound abnormalities were similar (22% vs 22%). Among children monitored, the rate of neurologic abnormalities, including cerebral palsy, increased from 16% during period I to 25% during period II and the rate of deafness increased from 3% to 7%. The overall rate of neurodevelopmental impairment (major neurosensory abnormality and/or Bayley Mental Developmental Index score of <70) increased from 26% to 36%. Compared with period I, in period II there were decreased rates of death (odds ratio [OR]: 0.3; 95% confidence interval [CI]: 0.2–0.4) and increased rates of survival with impairment (OR: 2.3; 95% CI: 1.7–3.3) but also increased rates of survival without impairment (OR: 1.7; 95% CI: 1.3–2.2). Compared with period I, for every 100 infants with birth weights of 500 to 999 g born in period II, 18 additional infants survived, of whom 7 were unimpaired and 11 were impaired. Conclusions. The improved survival rates in the 1990s occurred with an increased risk of significant neurodevelopmental impairment. Prospective parents of extremely low birth weight infants should be advised of this substantial risk, to facilitate decision-making in the delivery room.

[1]  M. Bax TERMINOLOGY AND CLASSIFICATION OF CEREBRAL PALSY , 1964, Developmental medicine and child neurology.

[2]  F. McLean,et al.  Intrauterine growth of live-born Caucasian infants at sea level: standards obtained from measurements in 7 dimensions of infants born between 25 and 44 weeks of gestation. , 1969, The Journal of pediatrics.

[3]  M. J. Bell,et al.  Neonatal Necrotizing Enterocolitis: Therapeutic Decisions Based upon Clinical Staging , 1978, Annals of surgery.

[4]  L. Papile,et al.  Incidence and evolution of subependymal and intraventricular hemorrhage: a study of infants with birth weights less than 1,500 gm. , 1978, The Journal of pediatrics.

[5]  L. Papile,et al.  INCIDENCE AND EVOLUTION OF SUBPENDYMAL AND INTRAVENTRICULAR HEMORRHAGE: A STUDY OF INFANTS WITH BIRTH WEIGHTS LESS THAN 1,500 GRAMS , 1978 .

[6]  J. Ellenberg,et al.  Children who "outgrew' cerebral palsy. , 1982, Pediatrics.

[7]  A. Ohlsson,et al.  Abnormal pulmonary outcomes in premature infants: prediction from oxygen requirement in the neonatal period. , 1988, Pediatrics.

[8]  C. Amiel‐Tison,et al.  Follow up studies during the first five years of life: a pervasive assessment of neurological function. , 1989, Archives of disease in childhood.

[9]  P. Rosenbaum,et al.  Decreased disability rate among 3-year-old survivors weighing 501 to 1000 grams at birth and born to residents of a geographically defined region from 1981 to 1984 compared with 1977 to 1980. , 1989, The Journal of pediatrics.

[10]  A. Fanaroff,et al.  Outcomes of extremely-low-birth-weight infants. , 1996, The New England journal of medicine.

[11]  R W Cooke,et al.  Birthweight specific trends in cerebral palsy. , 1990, Archives of disease in childhood.

[12]  L. Doyle,et al.  Audiologic assessment of extremely low birth weight infants: a preliminary report. , 1992, Pediatrics.

[13]  F. Stanley Survival and cerebral palsy in low birthweight infants: implications for perinatal care. , 1992, Paediatric and perinatal epidemiology.

[14]  N Paneth,et al.  Impact of improved survival of very low birth weight infants on recent secular trends in the prevalence of cerebral palsy. , 1993, Pediatrics.

[15]  R. J. Schechter Laser treatment of retinopathy of prematurity. , 1993, Archives of ophthalmology.

[16]  J. Horbar,et al.  Decreasing mortality associated with the introduction of surfactant therapy: an observational study of neonates weighing 601 to 1300 grams at birth. The Members of the National Institute of Child Health and Human Development Neonatal Research Network. , 1993, Pediatrics.

[17]  M. Allen,et al.  The Limit of Viability: Neonatal Outcome of Infants Born at 22 to 25 Weeksʼ Gestation , 1994 .

[18]  J. Scanlon,et al.  Effect of surfactant on morbidity, mortality, and resource use in newborn infants weighing 500 to 1500 g. , 1994, The New England journal of medicine.

[19]  E. Keeler,et al.  Effect of corticosteroids for fetal maturation on perinatal outcomes, February 28-March 2, 1994 , 1995 .

[20]  D K Stevenson,et al.  Very-low-birth-weight outcomes of the National Institute of Child Health and Human Development Neonatal Research Network, May 1991 through December 1992. , 1995, American journal of obstetrics and gynecology.

[21]  J. Tyson,et al.  Evidence-based ethics and the care of premature infants. , 1995, The Future of children.

[22]  K. Nelson,et al.  Prenatal and perinatal factors and cerebral palsy in very low birth weight infants. , 1996, The Journal of pediatrics.

[23]  D. J. Goldstein,et al.  Survival and developmental disability in infants with birth weights of 501 to 800 grams, born between 1979 and 1994. , 1997, Pediatrics.

[24]  C. Leonard,et al.  Outcome of extremely low birth weight infants (500 to 999 grams) over a 12-year period. , 1997, Pediatrics.

[25]  Neonatal risk factors for cerebral palsy in very preterm babies: case-control study , 1997, BMJ.

[26]  Improved outcome into the 1990s for infants weighing 500–999 g at birth , 1997, Archives of disease in childhood. Fetal and neonatal edition.

[27]  A. Fanaroff,et al.  Perinatal Correlates of Cerebral Palsy and Other Neurologic Impairment Among Very Low Birth Weight Children , 1998, Pediatrics.

[28]  S. Wardle,et al.  Increased survival and deteriorating developmental outcome in 23 to 25 week old gestation infants, 1990–4 compared with 1984–9 , 1998, Archives of disease in childhood. Fetal and neonatal edition.

[29]  J. Brooks-Gunn,et al.  The Infant Health and Development Program: Interim Summary , 1998, Journal of developmental and behavioral pediatrics : JDBP.

[30]  K. Linde,et al.  Liver enzyme elevations in patients treated with traditional Chinese medicine. , 1999, JAMA.

[31]  A. Fanaroff,et al.  Outcomes of children of extremely low birthweight and gestational age in the 1990's. , 1999, Early human development.

[32]  N. Bayley Bayley Scales of Infant Development , 1999 .

[33]  A. Fanaroff,et al.  Outcomes of children of extremely low birthweight and gestational age in the 1990s. , 2000, Seminars in neonatology : SN.

[34]  J. Hodgman,et al.  Treatment Decisions for Newborns at the Threshold of Viability: An Ethical Dilemma , 2000, Journal of Perinatology.

[35]  N. Paneth,et al.  Treatment decisions for the extremely premature infant. , 2000, The Journal of pediatrics.

[36]  M. Rebagliato,et al.  Treatment choices for extremely preterm infants: an international perspective. , 2000, The Journal of pediatrics.

[37]  A. C. Primavesi Neurologic and Developmental Disability after Extremely Preterm Birth , 2000 .

[38]  C R Bauer,et al.  Very low birth weight outcomes of the National Institute of Child health and human development neonatal research network, January 1995 through December 1996. NICHD Neonatal Research Network. , 2001, Pediatrics.

[39]  D. Streiner,et al.  Attitudes of parents and health care professionals toward active treatment of extremely premature infants. , 2001, Pediatrics.

[40]  A. Synnes,et al.  Survival, morbidity, and resource use of infants of 25 weeks' gestational age or less. , 2001, American journal of obstetrics and gynecology.

[41]  A. Jobe,et al.  Prospects for research in reproductive health and birth outcomes. , 2001, JAMA.

[42]  J. Tyson,et al.  Comparison of management strategies for extreme prematurity in New Jersey and the Netherlands: outcomes and resource expenditure. , 2001, Pediatrics.

[43]  R. Harper,et al.  Neonatal Outcome of Infants Born at 500 to 800 Grams From 1990 Through 1998 in a Tertiary Care Center , 2002, Journal of Perinatology.

[44]  P. Ubel,et al.  Fear of litigation may increase resuscitation of infants born near the limits of viability. , 2002, The Journal of pediatrics.

[45]  Walter Allan,et al.  Change in cognitive function over time in very low‐birth‐weight infants. , 2003, JAMA.

[46]  Z. Pavlova,et al.  Two‐Year Outcome of Infants Weighing 600 Grams or Less at Birth and Born 1994 Through 1998 , 2003, Obstetrics and gynecology.

[47]  L. Doyle,et al.  Executive functioning in school-aged children who were born very preterm or with extremely low birth weight in the 1990s. , 2004, Pediatrics.