Induction of labour using prostaglandin E2 pessaries.

The blanket use of prostaglandin E2 pessaries, as reported by Mr J H Shepherd and his colleagues (14 July, p 108), does concern me. While they did draw attention to the need for fetal monitoring in such patients, I wonder how satisfactorily this can be achieved, especially in relatively high-risk cases, under such circumstances and whether such monitoring could not be better achieved by direct fetal ECG monitoring after rupture of the membranes. Their suggestion that low-risk cases do not need monitoring under such circumstances must also be questioned. While prostaglandin given vaginally is undoubtedly effective in achieving cervical softening, be it by the effect of circulating oestradiol or, as we are currently assessing in this unit, by an effect on collagenase activity in the cervix, the response to such treatment is widely regarded as very variable--as noted in this series, where a number of patients laboured after a single administration and some failed to respond to two such administrations of prostaglandin E2. Its blanket use in a fixed-dose regimen must be questionable under such circumstances and it must be only a matter of time before the hypertonus already reported recurs with more serious consequences. The transfer of a patient in labour starting after the administration of prostaglandin E2 vaginally on the antenatal ward may not be always as rapid and smooth as is necessary if monitoring is to be instituted sufficiently early in labour to avoid occasional fetal asphyxia. A routine induction policy must carry with it some risk and I would be concerned to see it generally applied without the recognition of this problem.