External cephalic version of the non-cephalic presenting twin: a systematic review

Objective: Decreasing the primary cesarean delivery rate and associated maternal and fetal complications is a priority for obstetric care providers. External cephalic version (ECV) is a procedure recommended for women with singleton pregnancies where the fetus is malpresenting to avoid vaginal breech delivery, which is inherently riskier than cesarean delivery. However, little is known about this procedure in the context of twin gestations. Scheduled cesarean delivery is instead recommended for women with twin gestations where the presenting twin is not cephalic. Our aim is to evaluate the safety and efficacy of ECV in the setting of twin pregnancy where the presenting twin is not cephalic. We also present two patients with twin pregnancy at our institution that attempted ECV. Data sources: A systematic review of the following electronic databases was performed, searching from their inception until September 2019: Pubmed, Ovid, Scopus, and clinicaltrials.gov. Study eligibility criteria: All reported cases of ECV for a non-cephalic presenting twin were included. Studies were excluded if patients had contraindications to vaginal delivery and if they described ECV of the second twin only. Maternal demographics, procedure details, and outcomes data were collected. Study appraisal and synthesis methods: The primary outcome was a successful version of the presenting twin to the cephalic presentation following ECV. Statistical analysis involved calculating means, standard deviations, frequencies and percentages as appropriate. Results: Two case reports and one case series, totaling 22 patients, met inclusion criteria. Two additional patients attempted ECV at our institution. One completed ECV (for a total of 23 patients) while the other did not. This patient consented for ECV as Twin A was noted to be breeched upon presentation to labor and delivery but after receiving regional anesthesia, twin A was cephalic. No randomized controlled trials were identified. All were dichorionic pregnancies. Successful ECV of twin A occurred in 57% (13/23) of women and 48% (11/23) had a successful vaginal delivery. The majority were performed using regional anesthesia and a uterine relaxant (20/23). No serious adverse events occurred in any of the reports. Conclusions: ECV is insufficiently studied in twin pregnancy. Based on very limited data, it appears feasible to turn the non-cephalic presenting twin. Additional randomized controlled trials are needed to further evaluate the safety and efficacy of this procedure for a non-cephalic presenting twin.