Fetal Macrosomia Management

Diagnosis and Risk Factors

The American Academy of Family Physicians recommends that vaginal delivery is not contraindicated for women with estimated fetal weights up to 5,000g in non-diabetic women, but prophylactic cesarean delivery should be considered when estimated fetal weight exceeds 5,000g in non-diabetic women or 4,500g in diabetic women 1
The risk of shoulder dystocia increases to 9.2-24% when birth weight exceeds 4,500g in non-diabetic women, and brachial plexus injury and clavicular fracture have an 18-21 fold increased risk with birth weight >4500g 1
The risk of clavicular fracture is 10-fold increased with macrosomia, and the diagnosis of fetal macrosomia is imprecise, with ultrasound biometry being no better than clinical palpation 1

The American Academy of Family Physicians recommends that cesarean delivery should be performed in cases of midpelvic arrest with suspected macrosomia, except in extreme emergencies, and that midpelvic operative vaginal delivery should be avoided with suspected macrosomia 1
Prolonged second stage with estimated fetal weight > 4,500g is an indication for cesarean delivery, and elective cesarean delivery reduces but does not eliminate the risk of birth trauma 1
Induction of labor is not recommended for suspected macrosomia alone, as it may double the risk of cesarean delivery without reducing shoulder dystocia or newborn morbidity, and current evidence does not support early induction of labor for suspected macrosomia 1

The American Academy of Family Physicians states that suspected fetal macrosomia is not a contraindication to attempted vaginal birth after a previous cesarean delivery, and the American College of Obstetricians and Gynecologists recommends delivery at 37 weeks for severe fetal macrosomia cases, at 38-39 weeks for moderate cases, and consideration of cesarean delivery only when estimated fetal weight exceeds 5000g in non-diabetic women or 4500g in diabetic women 2, 1
Earlier delivery may be indicated with absent end-diastolic velocity (deliver at 33-34 weeks) or reversed end-diastolic velocity (deliver at 30-32 weeks), and with normal umbilical artery Doppler, delivery is recommended at 38-39 weeks of gestation 2

Once fetal growth restriction is diagnosed, serial umbilical artery Doppler assessment should be performed, with weekly umbilical artery Doppler evaluation suggested for severe fetal growth restriction, and weekly cardiotocography testing after viability for fetal growth restriction without absent/reversed end-diastolic velocity 2