Has pelvimetry a role in current obstetric practice?

Radiological pelvimetry is still requested in some centres before planned vaginal delivery for breech presentation or following a previous caesarean section. In a retrospective review of the utilisation of pelvimetry in 167 cases in our department, 103 (62%) and 64 (38%) had pelvimetry in the postnatal and antenatal periods respectively. Antero-posterior inlet and outlet diameters were inadequate in 19.2% and 16.2% respectively. Of those who had postnatal pelvimetry, only 36 (35%) returned to our unit for further confinement and the caesarean section rate in this group was 75%. The main indications for antenatal pelvimetry were breech presentation (28), previous caesarean section (23) and anticipated cephalopelvic disproportion (13). The caesarean section rates in these groups were 82%, 70% and 45% respectively. However, the emergency caesarean section rate in the breech presentation group was 28%. Nine patients (32%) of those who had breech presentation and delivered by elective caesarean section had normal pelvic measurements. Pelvimetry should only be performed if its results will influence the mode of delivery. Pelvimetry may be useful in selecting fetuses with breech presentation for vaginal delivery or elective caesarean section. However it would increase the likelihood of caesarean section in cephalic presentation.