Relations between maternal height, shoe size, and the success of vaginal delivery in birth weight over 4000 g

Objective: Macrosomia is associated with increased risk of fetal and maternal complications such as trauma during birth, cesarean delivery, postpartum hemorrhage, and shoulder dystocia. Sonographic estimation of fetal weight is imprecise particularly in excessively large fetuses, prompting the need for additional measures to assess the feasibility of vaginal delivery of a macrosomic newborn and thus improve prenatal consultation. Materials and methods: This retrospective case–control study included women who delivered a singleton macrosomic newborn (birth weight>4,000 g), either vaginally (N = 762) or by urgent cesarean delivery during labor (N = 109). Using multivariable analysis, we examined correlations of maternal height≥170 cm and shoe size≥40 with successful vaginal delivery. Results: Women who delivered vaginally had lower mean intrapartum BMI (p < 0.001) and lower rate of gestational diabetes (p = 0.003). Women with a shoe size≥40 were 2.2 times more likely to give birth vaginally. Cesarean section rate was 5.9 % among women with height≥170 cm and shoe size≥40; and 16.5 % among women with height<170 cm and shoe size<40. Multivariable analysis, adjusted for gestational diabetes, parity, and BMI, revealed that shoe size≥40 and maternal height≥170 cm correlated with success in vaginal delivery, OR = 3.1 (95%CI 1.3–7.3, p = 0.009). Conclusion: Shoe size and maternal height may help predict success of vaginal birth of the macrosomic newborns.