Pregnancy following childhood hemipelvectomy: labor dystocia attributable to absent bony guidance and pelvic distortion-a case report and literature review.

BACKGROUND: Pregnancy after childhood hemipelvectomy is rare, and contemporary guidance on fertility, preconception counseling, and delivery planning remains limited. Altered pelvic anatomy may affect fetal descent and rotation ; however, the optimal mode and delivery timing should be individualized. CASE: A 30-year-old primigravida, with a history of right hemipelvectomy for osteosarcoma, conceived spontaneously after regular menstrual cycles. Fertility preservation was not performed during childhood treatment, and formal preconception counseling with an obstetric team was not provided. After antenatal assessment, a trial of labor was planned under close supervision. During induction at 38 weeks of gestation, vaginal examination and transabdominal ultrasonography revealed poor fetal head descent and deviation toward the pelvic defect, with suspected rotational failure. Cesarean delivery was performed after persistently poor progress and non-reassuring fetal heart rate patterns. Intraoperatively, uterine rotation with rightward cervical deviation and leftward fundal deviation was observed. CONCLUSION: After hemipelvectomy, delivery planning should consider the pelvic anatomy, maternal functional status, anesthetic issues, and risk of prolonged labor. Intrapartum ultrasonography may help identify fetal head deviation and malrotation ; however, timely transition to cesarean delivery should be considered when poor descent persists.