J Korean Pediatr Soc.  2003 Dec;46(12):1194-1199.

Change in the Limit of Viability of Fetal Infants

• Choi CW
• Hwang JH
• Shim JW
• Kim SS
• Ko SY
• Lee EK
• Chang YS
• Park WS

Abstract

PURPOSE
To determine the change in the limit of viability in fetal infants and the incidence of major complications in neonatal intensive care unit(NICU) at Samsung Medical Center(SMC).
METHODS
Sevety-three infants weighing less than 800 g at birth and 117 infants born earlier than 27 weeks gestational age, who were admitted to NICU at SMC between November 1994 and December 2002, were enrolled. Their medical records were reviewed with a focus on the survival and major complications, including chronic lung disease, retinopathy of prematurity, intraventricular hemorrhage, and periventricular leukomalacia. The limit of viability in fetal infants was defined as the birth weight or gestational age at which a 50% survival rate is reached and the incidence of major complications were compared by period(period I : Nov. 1994-Dec. 1998, period II : Jan. 1999-Dec. 2002).
RESULTS
The limit of viability in fetal infants was markedly lowered from birth weight range of 800-900 g or gestational age range of 26+0-26+6 weeks in period I to birth weight range of 600-700 g or gestational age range of 24+0-24+6 weeks in period II. The incidence rates of major complications at the limit of viability were all less than 50% in period II. There was no definite trend toward increased incidence of major complications as birth weight get smaller and gestational age get younger.
CONCLUSIONS
Our results indicate that at present, fetal infants whose body weight is over 600 g, or whose gestational age is over 24 weeks should be resuscitated vigorously. The risk of major complications at this birth weight or gestational age seems to be not greater than that at a bigger birth weight or an older gestational age.

Keyword

Viability; Survival rate; Fetal infants; Limit

MeSH Terms

Birth Weight
Body Weight
Gestational Age
Hemorrhage
Humans
Incidence
Infant*
Infant, Newborn
Intensive Care, Neonatal
Leukomalacia, Periventricular
Lung Diseases
Medical Records
Parturition
Retinopathy of Prematurity
Survival Rate