Postconceptional age of surviving preterm low-birth-weight infants at hospital discharge
J. S. Rawlings and J. S. Scott
Department of Pediatrics, Madigan Army Medical Center, Tacoma, Wash, USA.
BACKGROUND: Prediction of the duration of hospital stay of preterm,
low-birth-weight infants currently requires inconvenient referral to
published tables. OBJECTIVE: To determine whether postconceptional age
(gestational age plus chronologic age) could serve as a useful clinical
marker for the more convenient prediction of individual durations of
hospital stay. DESIGN: Case series. Setting: Regional military teaching
medical center with level III obstetric and neonatal services. PATIENTS:
Nine hundred sixty surviving preterm, low-birth-weight infants in the
neonatal intensive care unit. MAIN OUTCOME MEASURE: The strength of the
relationship of birth weight to postconceptional age at the time of
discharge was tested by analysis of variance. RESULTS: Postconceptional age
at the time of hospital discharge varied in a highly predictable manner
with birth weight (P<.001). The mean and variance were greatest for
infants with very low birth weights and decreased with increasing birth
weight. Postconceptional age at the time of discharge reached a minimum of
36.0 +/- 1.4 weeks (mean +/- SD) for infants with birth weights of 1750 to
2240 g. CONCLUSIONS: Most preterm, low-birth-weight infants meet current
eligibility criteria for hospital discharge at a postconceptional age of 35
to 37 weeks. This level of maturity is sufficiently predictive to serve as
a convenient, easy-to-remember clinical marker for expected durations of
hospital stay. For infants with birth weights of less than 1000 g,
discharge at a post-conceptional age of 37 to 42 weeks is a more realistic
expectation.
