Clinical Patterns in Extremely Preterm (22 to 24 Weeks of Gestation) Infants in Relation to Survival Time and Prognosis

ABSTRACT

We investigated time-related predictors of death or neurological sequelae in extremely preterm infants (EPI) born at 22 to 24 weeks' gestation by categorizing clinical patterns according to their survival time and morbidity. Data on 113 infants born at 22 to 24 weeks' gestation from January 1991 through April 2006 were analyzed by a case-control approach. Cesarean section, Apgar score ≤ 3 at 5 minutes, and pulmonary hypoplasia were significantly associated with death at < 24 hours of life. Among infants who survived ≥ 24 hours, pulmonary hemorrhage and intraventricular hemorrhage (IVH) were significantly associated with death by day 6. Among those surviving ≥ 7 days, sepsis and severe IVH were significantly associated with death. Assessment of survivors at a minimum follow-up period of 2 years revealed that protracted mechanical ventilation was significantly associated with a poor neurological outcome. There are various characteristic key events in relation to the outcome at different ages of life in EPI born at 22 to 24 weeks' gestation. Clinicians and parents should discuss management options for the infant on the basis of these findings.

KEYWORDS

Extremely preterm infant - limit of viability - mortality - morbidity - predictor

REFERENCES

• 1 Hoekstra R E, Ferrara B, Couser R J, Payne N R, Connet J E. Survival and long-term neurodevelopmental outcome of extremely premature infants born at 23–26 weeks' gestational age at a tertiary center.  Pediatrics. 2004;  113 e1-e6
• 2 Tyson J E, Parikh N A, Langer J, Green C, Higgins R D. Intensive care for extreme prematurity—moving beyond gestational age.  N Engl J Med. 2008;  358 1672-1681
• 3 Meadow W, Reimshisel T, Lantos J. Birth weight-specific mortality for extremely low birth weight infants vanishes by four days of life: epidemiology and ethics in the neonatal intensive care unit.  Pediatrics. 1996;  97 636-643
• 4 Ambalavanan N, Baibergenova A, Carlo W A, Saigal S, Schmidt B, Thorpe K E. Early prediction of poor outcome in extremely low birth weight infants by classification tree analysis.  J Pediatr. 2006;  148 438-444
• 5 Papile L A, Burstein J, Burstein R, Koffler H. Incidence and evolution of the subependymal intraventricular hemorrhage: a study of infants with weights less than 1500 grams.  J Pediatr. 1978;  92 529-534
• 6 Bell M J, Ternberg J L, Feigin R D et al.. Neonatal necrotizing enterocolitis: therapeutic decisions based upon clinical staging.  Ann Surg. 1978;  187 1-7
• 7 Kusuda S, Fujimura M, Sakuma I et al.. Morbidity and mortality of infants with very low birth weight in Japan: center variation.  Pediatrics. 2006;  118 e1130-e1138
• 8 Shankaran S, Fanaroff A A, Wright L L et al.. Risk factors for early death among extremely low-birth-weight infants.  Am J Obstet Gynecol. 2002;  186 796-802
• 9 Bottoms S F, Paul R H, Iams J D et al.. Obstetrical determinants of neonatal survival: influence of willingness to perform cesarean delivery on survival of extremely-low-birth-weight infants. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Unites.  Am J Obstet Gynecol. 1997;  176 960-966
• 10 Vergani P, Ghidini A, Locatelli A et al.. Risk factors of pulmonary hypoplasia in second trimester premature rupture of membranes.  Am J Obstet Gynecol. 1994;  170 1359-1364
• 11 Covert R F, Domanico R S, Barman N, Khoshnood B, Dean R P, Lester L A. Prophylactic indomethacin: effect on pulmonary hemorrhage & bronchopulmonary dysplasia in surfactant-treated infants < 1250 grams.  Pediatr Res. 1996;  39(Suppl 2) 203
• 12 Evans N, Kluckow M. Early ductal shunting and intraventricular hemorrhage in ventilated preterm infants.  Arch Dis Child Fetal Neonatal Ed. 1996;  75 F183-F186
• 13 Garland J, Buck R, Weinberg M. Pulmonary hemorrhage risk in infants with clinically diagnosed patent ductus arteriosus: a retrospective cohort study.  Pediatrics. 1994;  94 719-723
• 14 Linder N, Haskin O, Levit O, Klinger G, Prince T, Naor N. Risk factors for intravascular hemorrhage in very low birth weight premature infants: a retrospective case-control study.  Pediatrics. 2003;  111 e590-e595
• 15 Fleiss J L. Statistical Methods for Rates and Proportions, 2nd ed. New York; John Wiley & Sons 1981: 61-64
• 16 Meadow W, Frain L, Ren Y, Lee G, Soneji S, Lantos J. Serial assessment of mortality in the neonatal intensive care unit by algorithm and intuition: certainty, uncertainty, and informed consent.  Pediatrics. 2002;  109 878-886
• 17 Walsh M C, Morris B H, Wrage L A et al.. Extremely low birthweight neonates with protracted ventilation: mortality and 18-month neurodevelopmental outcomes.  J Pediatr. 2005;  146 798-804
• 18 American Academy of Pediatrics, Canadian Paediatric Society. . Postnatal corticosteroids to treat or prevent chronic lung disease in preterm infants.  Pediatrics. 2002;  109 330-338
• 19 Walsh M C, Yao Q, Horbar J D, Carpenter J H, Lee S K, Ohlsson A. Changes in the use of postnatal steroids for bronchopulmonary dysplasia in 3 large neonatal networks.  Pediatrics. 2006;  118 e1328-e1335