The timing of the first meconium has been considered a marker for proper gastrointestinal function in newborn infants. There is limited information about low birth weight infants and the passage of the first meconium. We retrospectively collected data from hospital records on 354 infants who were admitted to the NICU. We divided the infants into three groups based on the birthweights: < 1000grams (gm), 1001-1500 gm and >1500gm. Many variables were studied including Apgar score at 5 minutes, presence of RDS, exposure to maternal betamethasone and resuscitation of the infant in the delivery room. We used the Chi square and simple regression for stastistical analysis. Results: the three groups with the data are shown in the Table. (n=number, Ap-5′=Apgar at 5 minutes, Mec-Hr=age in hours at first meconium passage, Resus= resuscitation in delivery room, C/S=cesarean section, Mat-B= maternal betamethasone, BW=birth weight±SD,*=median values) Conclusion: In our data we found that there was a significant difference in the timing of the first meconium between the three groups (p<0.0001). The incidence of RDS also was significantly different between the three groups (p=0.02). There were no significant differences in maternal betamethasone exposure, Apgar scores at 5 minutes, neonatal resuscitation in the delivery room or mode of delivery. Thus, the time to passage of the first meconium in low birth weight infants appears to be related to degree of prematurity, but not to other perinatal events.

Table 1