Female sterilisation: National Women's Hospital 1988-9

To determine the failure rate of all female sterilisation procedures performed at National Women's Hospital in order to identify ways of improving the service.

A review was made of all sterilisation procedures performed at National Women's Hospital in 1988 and 1989. All patient notes and theatre records were examined. A consumer questionnaire was mailed to all patients monthly for 3 months. If there was no response efforts were made to contact these women via their last known general practitioner. Epsom Day Hospital where 95% of all terminations of pregnancy in Auckland are performed also examined their records.

1094 procedures were performed at National Women's Hospital in Auckland during 1988 and 1989. Failures were classified into two groups: those pregnant at the time of surgical procedure (administrative failures) and those pregnant after the procedure (surgical failure). There were 15 surgical failures (1.4%). Laparoscopy using Filshie clips was the most common method used and had a 1.2% surgical failure rate. Registrars had a 1.3% failure rate, consultants 1.9% and when both a consultant and registrar performed the procedure a failure rate of 0.7% was recorded. Eighty-six percent (6/7) of women who had a subsequent laparotomy after a failed sterilisation were found to have surgical misapplication of the occlusive device. There were 7 (0.6%) women who were pregnant at the time of the procedure. There were no patient or procedure-related factors which were associated with failures.

Sterilisation is associated with a significant failure rate. Contraception counselling at the time of booking for the procedure needs to be improved. Preoperative pregnancy testing should be introduced to avoid sterilisation procedures in early pregnancy. Surgical misapplication of devices was a common cause of failure, not recanalisation as found elsewhere. From this review it would appear that the involvement of two surgeons lowers the failure rate.