Neonatal Macrosomia: What are the Risk Factors and Implications?

Background: A birth weight over 4000g, regardless of gestational age, is the definition of macrosomia. It affects about 3-15% of the babies born worldwide and is associated with neonatal and maternal complications.

Objective: To describe the risk factors and complications present in macrosomic children born in a tertiary center.

Methods: Review of clinical records of children born between July and December 2018. Descriptive analysis of demographic data, risk factors for macrosomia and neonatal and maternal complications.

Results: There were a total of 1346 births, 4,9% (n=66) of them corresponding to macrosomic newborns, with male predominance (74%). Regarding maternal factors: maternal mean age was 30,2 ± 6,2 years; 1,6% presented pre-eclampsia; 10,9% had diabetes (1/7 pre-gestational and 6/7 gestational diabetes); 9,4% were obese; 4,7% smokers and 31,3% had a previous macrosomic newborn. In relation to newborn factors: 15,6% had a prenatal diagnosis of macrosomia; the mean gestational age was 39,9 ± 1 weeks; mean birth weight of 4356,7 ± 304,4 grams with 41% large for gestational age (P>90). At least one complication was present in 81% of the newborns (hyperbilirubinemia in 28,1%, neonatal hypoglycemia in 23,4%, shoulder dystocia in 10,9%, neonatal respiratory distress syndrome in 10,9%, brachial plexus palsy in 4,7%, clavicle fracture in 3,1%, weight loss greater than 10% in 3,1%,) and 6% needed hospitalization in a neonatal care unit. Maternal postpartum hemorrhage occurred in 1,6% and 56,3% (n=48) had perineal laceration.

Conclusion: As according to the literature, our rate of macrosomic newborns was similar to the worldwide data and there was also a male predominance. There was a high neonatal complication rate in our sample. The prevention of modifiable risk factors for macrosomia and its prenatal diagnosis is crucial to reduce associated newborn and maternal morbidity.