Outcomes of macrosomic infants in a nurse-midwifery service

The purpose of this study was to compare outcomes of term infants of average birth weight with outcomes of large infants in a nurse-midwifery service. A retrospective study design was used. Data were retrieved from a computer data base that contained information from a data form routinely completed for all births. Subjects were women cared for by the nurse-midwives including those for whom the birth was conducted by a physician. The final n study population was 2,228; 322 (14.5%) of the infants weighed 4,000 g or more. Women who delivered large infants had a significantly higher prepregnant body mass index and pregnancy weight gain. Shoulder dystocia occurred more often in large infants; however, newborn intensive care unit admission rates did not differ between the average birth weight and the large infants. Apgar scores at 1 and 5 minutes were significantly lower for infants weighing > or = 4,500 g compared to those with birth weights of 2,500-3,999 g and those 4,000-4,449 g; however, these differences were not clinically significant. A trend for fewer occurrences of shoulder dystocia in the side-lying birth position was observed. Logistic regression predicting poor Apgar scores (< 7) showed parity as a protective factor and increased gestational age and higher maternal body mass index as predictive of low Apgar scores. Large infants had birth outcomes comparable to those reported by others in the medical literature, suggesting that nurse-midwifery management, including consultation with physician colleagues, can be appropriate and safe.