To evaluate the factors which contribute to the time of the first stool and the first urine passage.

We retrospectively reviewed a chart of 1,221 infants ??4 weeks of gestational age admitted to the normal newborn nursery of Il Sin Christian Hospital, Busan, from November 2004 to April 2005. We compared the time to first stool and urine according to maternal factors(maternal age, parity, mode of delivery, meconium-stained amniotic fluid, and maternal diabetes) and infant factors (gender, Apgar score, gestational age, type of feeding during first 24 hours, age at the first feeding, number of feeds during the first 12 hours and age at discharge).

In total, 95.3 percent of our infants had passed their first stool by 24 hours and 99.8 percent of them had a stool by 36 hours. A total of 95.8 percent of our infants had passed urine by 24 hours of age and 98.3 percent of them by 36 hours. Comparing preterm and term infants, the time to first urine is 6.5±5.8 hours and 12.1±6.6 hours, respectively( P =0.000). The time to first stool is 20.7±13.5 hours and 10.0±6.3 hours, respectively( P =0.000) Early-fed infants were significantly earlier in time to first urine( P =0.023) and first stool( P =0.012). There was no statistically significant relationship between the number of feeds in 0-12 hours, mode of delivery, Apgar score, parity, gender, type of feeding, maternal diabetes and the time of the first urine and first stool.

Gestational age, birth weight and age at first feeding were significantly related to the time of the first urine and first stool passage. When there is delayed passage of the first urine and first stool, we should consider close observation of other associated symptoms and other factors previously mentioned, to avoid extensive evaluation and intervention.