Fetal macrosomia can cause a baby to become wedged in the birth canal (shoulder dystocia), sustain birth injuries, or require the use of forceps or a vacuum device during delivery (operative vaginal delivery). Sometimes a C-section is needed. Genital tract lacerations.
https://www.mayoclinic.org/diseases-conditions/fetal-macrosomia/symptoms-causes/syc-20372579

