Deflexion of the fetal head in breech presentation. Incidence, management, and outcome.

The deflexion attitude of the fetal head in 223 consecutive breech deliveries was radiologically evaluated and classified into four grades. Additional x-ray pelvimetry was performed on all primiparas (136 cases). Extended (35 cases with deflexion angle of 90 degrees or less) and hyperextended (2 cases with angle of more than 90 degrees) variants were found in 16.4%. In the cases of hyperextension, the patients had elective cesarean section, while in cases of other variants they were delivered vaginally in the absence of other indications to cesarean section. The overall cesarean section rate was 17.5%. No cases of perinatal mortality were recorded. Two hundred and sixteen babies had a 1-minute Apgar score of 7--10, 6 had a score of 4--6, and 1 had a score of 2. Only 1 of the 7 asphyxiated babies was of the group of 35 patients classified as having an extended variant. These favorable results confirm the importance of the radiologic assessment of the deflexion angle as a clinical tool.