title: Survival and neurodevelopmental outcome of preterm infants born at 22-24 weeks of gestational age.
abstract: BACKGROUND
  The limits of viability in extremely premature infants are challenging for any neonatologists in developed countries. The neurological development and growth of extremely preterm infants have come to be the emerging issue following the management in the neonatal intensive care unit.
  
  
  OBJECTIVE
  To assess potential associations between changes in practice and survival/neurodevelopmental outcome, and clinical outcomes of extremely preterm infants born at the limit of viability studied in a tertiary center.
  
  
  METHODS
  A retrospective study enrolled 51 infants who had no congenital disorders, and were born at 22-24 weeks of gestational age (GA) in 2000-2009 in our institution. Clinical variables and interventions were studied with regard to one-year survival and developmental quotient (DQ) at 3 years of age.
  
  
  RESULTS
  The one-year survival rate of 24 preterm infants born in 2005-2009 (79%) was higher than that of the 27 infants born in 2000-2004 (52%, p = 0.04). Infants born after 2005 underwent less tocolysis (54 vs. 94%, p < 0.01) and more frequently antenatal steroid therapy (32 vs. 6%, p = 0.01) than those born before 2004. The post-2005 survivors (n = 19) received more frequently indomethacin therapy (89 vs. 50%, p = 0.03) and early parenteral nutrition (95 vs. 36%, p < 0.01) than the pre-2004 survivors (n = 14). There were no differences in the proportion of infants who attained a DQ of >50 at 3 years of age between pre-2004 (9/13, 69%) and post-2005 groups (10/17, 59%). Multivariate analysis indicated that extremely premature birth at GA <24 weeks was the sole critical factor for a DQ of >50 in survivors.
  
  
  CONCLUSIONS
  The perinatal care after 2005 improved the overall survival rate, but not the neurological outcome of preterm survivors at the limit of viability. Neurodevelopmental impairments were associated with extremely premature birth at GA <24 weeks.
authors.affiliation: Comprehensive Maternity and Perinatal Care Center, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ochiai
authors.forename: Tadamune
authors.initials: T
authors.lastname: Kinjo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takahata
authors.forename: Mariko
authors.initials: M
authors.lastname: Iwayama
authors.forename: Takeru
authors.initials: T
authors.lastname: Abe
authors.forename: Kenji
authors.initials: K
authors.lastname: Ihara
authors.forename: Shouichi
authors.initials: S
authors.lastname: Ohga
authors.forename: Kotaro
authors.initials: K
authors.lastname: Fukushima
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Kato
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Taguchi
authors.forename: Toshiro
authors.initials: T
authors.lastname: Hara
mesh_terms: D001921:Brain / Q000254:growth & development*; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D052577:Infant, Extremely Low Birth Weight / Q000254:growth & development; D062071:Infant, Extremely Premature / Q000254:growth & development; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis* / Q000401:mortality* / Q000503:physiopathology; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate