Moms-to-be warned over use of fetal heart rate monitors

In this week's BMJ, Dr Thomas Aust and colleagues from the Department of Obstetrics and Gynaecology at Arrowe Park Hospital, Wirral describe the case of a 27 year old woman who presented to their labour ward 32 weeks into her first pregnancy with reduced fetal movements.

She had first noted a reduction in her baby's activity two days earlier but had used her own Doppler device to listen to the heartbeat and reassured herself that everything was normal.

Further monitoring by the antenatal care team was not reassuring and the baby was delivered by caesarean section later that evening. The baby remained on the special care baby unit for eight weeks and is making steady progress.

A hand-held Doppler device assesses the presence of fetal heart pulsations only at that moment, and it is used by midwives and obstetricians to check for viability or for intermittent monitoring during labour, explain the authors. In untrained hands it is more likely that blood flow through the placenta or the mother's main blood vessels will be heard.

Following this case, they searched the internet and found that a fetal Doppler device could be hired for £10 a month or bought for £25-50 (ebay.co.uk). Although the companies offering sales state that the device is not intended to replace recommended antenatal care, they also make claims such as "you will be able to locate and hear the heartbeat with excellent clarity" (hi-baby.co.uk).

It is difficult to say whether self monitoring altered the outcome in this case, say the authors. But they now have posters in their antenatal areas recommending that patients do not use these devices.

Source: British Medical Journal (news : web)