(445) Does a Sonographic Estimation of Macrosomia Effect Perinatal Outcomes?

Macrosomia has been associated with significant delivery complications. An accurate fetal weight assessment is challenging particularly in macrosomic fetuses. We aimed to evaluate whether prenatal awareness of macrosomia effects maternal and neonatal outcomes.

Study Design:

A retrospective study was conducted between February 2020 to January 2022 in a large tertiary hospital. The study population consisted of singleton deliveries with macrosomia (defined as birthweight ≥4,000 grams). We compared delivery outcomes between women with a sonographic estimation of macrosomia to those that were incorrectly estimated as appropriate-for-gestational-age (AGA). Sonographic fetal weight estimations were performed within 14 days prior to delivery. Elective cesarean deliveries (CD) were excluded.

Logistic regression models were constructed to adjust for confounders.

Results:

During the study period, there were 816 deliveries of macrosomic neonates. Of them, 623 were thought to be AGA, while 193 were estimated as macrosomic. Patients with suspected macrosomia had a significantly higher risk for CD. In the AGA group, there were higher rates of arrest of descent, vacuum extraction deliveries and episiotomies during labor. In contrast, other second stage of labor complications such as hemorrhagic complications, perineal tears and shoulder dystocia were not significantly different between the groups (Table). There were no differences in neonatal outcomes.

In the multivariate analysis, an incorrect estimation of AGA was found to be protective of CD (adjusted OR=0.39, CI=0.25-0.61, p< 0.001), and independently associated with arrest of descent (adjusted OR=16.27, CI=3.24-81.79, p=0.001).

Conclusion:

Among macrosomic neonates, prenatal estimation of macrosomia is a significant risk factor for CD. There is more than threefold increased risk of incorrect prenatal weight estimation among these neonates. Arrest of descent is independently associated with an incorrect estimation of fetal weight.