Maternal and neonatal outcomes of macrosomic pregnancies

BACKGROUND: To compare maternal and neonatal outcomes of term macrosomic and adequate for gestational age (AGA) pregnancies. MATERIAL/METHODS: A retrospective analysis was performed on all term singleton macrosomic (birth weight ≥4000 g) and AGA (birth weight >10(th) percentile and <4000 g) pregnancies delivered at our hospital between 2004 and 2008. Data collected included maternal age, gestational age at delivery, mode of delivery, birth weight, fetal gender, maternal and neonatal complications. Comparisons were made between macrosomic and AGA pregnancies and between different severities of macrosomia (4000–4250 g, 4250–4500 g and ≥4500 g). RESULTS: The study population comprised of 34,685 pregnancies. 2077 neonates had birth weight ≥4000 g. Maternal age and gestational age at delivery were significantly higher for macrosomic neonates. Significantly more macrosomic neonates were born by cesarean section, and were complicated with shoulder dystocia, neonatal hypoglycemia, and had longer hospitalization period (both in vaginal and cesarean deliveries). Specifically, the odds ratio (OR) relative to AGA pregnancies for each macrosomic category (4000–4250 g, 4250–4500 g and ≥4500 g) of shoulder dystocia was 2.37, 2.24, 7.61, respectively, and for neonatal hypoglycemia 4.24, 4.41, 4.15, respectively. The risk of post partum hemorrhage was statistically increased when birth weight was >4500 g (OR=5.23) but not for birth weight between 4000–4500 g. No differences were found in the rates of extensive perineal lacerations between AGA and the different macrosomic groups. CONCLUSIONS: Macrosomia is associated with increased rate of cesarean section, shoulder dystocia, neonatal hypoglycemia, and longer hospitalization, but not associated with excessive perineal tears. Increased risk of PPH was found in the >4500g group.