Vacuum delivery at The Maternity Hospital Kuala Lumpur: a comparison of metal and silicone cups.

Singapore medical journal

PubMedID: 8783915

Lee HY, Subramaniam N, Nordin MM. Vacuum delivery at The Maternity Hospital Kuala Lumpur: a comparison of metal and silicone cups. Singapore Med J. 1996;37(1):55-60.
OBJECTIVE
To compare the advantages and disadvantages of the New Bird metal cups and silicone cups in terms of maternal and foetal outcome. To study the adverse effects and factors associated with failed vacuum deliveries.

DESIGN
A prospective randomised study of all vacuum deliveries from 1 December 1991 to 31 April 1992. The Hanshin electrical vacuum pump was used.

SETTING
A large obstetric unit-The Maternity Hospital Kuala Lumpur (MHKL).

SUBJECTS
Seventy-two consecutive patients where vacuum deliveries were indicated. Forty had metal and 32 had silicone cups. Another 7 vacuum deliveries using the manual vacuum pump were excluded.

MAIN OUTCOME MEASURES
Success rate of vaginal delivery, birth canal injuries, post-partum haemorrhage, duration of hospital stay, Apgar score, foetal injuries (scalp-ecchymosis, haematomas) neonatal jaundice, the rate of special care nursery (SCN) admission and neonatal mortality rate.

RESULTS
Failure to deliver with silicone cups alone was 21.9% compared to 10% for metal cups alone. Material morbidities and serious foetal scalp injuries were almost the same in both cups. However, minor foetal scalp injuries were significantly lower with silicone cups. Maternal height and baby's weight had no independent predictive values for successful vacuum delivery. When the foetal head was palpable per abdomen, the failure rate was 54.5% compared to 8.2% when it was not. Failed vacuum deliveries were associated with increased maternal and foetal morbidities.

CONCLUSION
Silicone cups and metal cups can be equally dangerous to the baby. Although our sample size was small, we recommend that vacuum delivery be avoided if the foetal head is palpable per abdomen.