POSTCONCEPTIONAL AGE OF SURVIVING PRETERM LOW-BIRTH-WEIGHT INFANTS ATHOSPITAL DISCHARGE

Background: Prediction of the duration of hospital stay of preterm, lo w-birth-weight infants currently requires inconvenient referral to pub lished tables. Objective: To determine whether postconceptional age (g estational age plus chronologic age) could serve as a useful clinical marker for the more convenient prediction of individual durations of h ospital stay. Design: Case series. Setting: Regional military teaching medical center with level III obstetric and neonatal services. Patien ts: Nine hundred sixty surviving preterm, low-birth-weight infants in the neonatal intensive care unit. Main Outcome Measure: The strength o f the relationship of birth weight to postconceptional age at the time of discharge was tested by analysis of variance. Results: Postconcept ional age at the time of hospital discharge varied in a highly predict able manner with birth weight (P<.001). The mean and variance were gre atest for infants with very low birth weights and decreased with incre asing birth weight. Postconceptional age at the time of discharge reac hed a minimum of 36.0+/-1.4 weeks (mean+/-SD) for infants with birth w eights of 1750 to 2240 g. Conclusions: Most preterm, ion-birth-weight infants meet current eligibility criteria for hospital discharge at a postconceptional age of 35 to 37 weeks. This level of maturity is suff iciently predictive to serve as a convenient, easy-to-remember clinica l marker for expected durations of hospital stay. For infants with bir th weights of less than 1000 g, discharge at a postconceptional age of 37 to 42 weeks is a more realistic expectation.