A foetal heart monitor designed by Indian scientists can save unborn infants in complicated pregnancies.
Developed by A.K. Mittra, from the Manoharbhai Patel Institute of Engineering and Technology in Maharashtra, and his colleagues, the simple device comprises a two-microphone system that can monitor foetal heart rate (FHR) when the mother is resting and asleep.
During complex pregnancies that end in preterm labour, miscarriage or foetal death, problems usually occur over days.
Regular ultrasound monitoring of foetal development can spot some problems but too frequent ultrasound monitoring is associated with health risks. Moreover, it cannot continually assess foetal heart rate.
However, disturbances in FHR, particularly regular sudden drops in rate for up to one minute, can occur long before an underlying problem is reflected in the form of other symptoms.
A serious drop in FHR is most likely to occur at night just before the pregnant woman lies down to sleep. At this time, she is most relaxed and her own heart rate drops, which leads to a lowering of her blood pressure, and in a susceptible fetal a problematic drop in its heart rate.
"Monitoring FHR during a woman's most restful hours at home and providing urgent medical assistance in case of abnormality will prove to be very effective in the prevention of stillbirth and other prenatal complexities," the researchers say.
They have now developed a device based on two small acoustic sensors that can easily monitor FHR and feed the information to a wave analyser in a bedside personal computer connected to the internet.
The first microphone is attached to the mother's abdomen to pick up the sound of foetus' heartbeat. The second is attached at a reasonable distance to pick up ambient and bodily noise.
Computer software can then subtract the "noise" channel from the foetal sound to produce a "wav" file that can be further analysed for medical anomalies.
The team points out that they have successfully tested their monitoring system on several women at various stages of pregnancy, said an Eurekalert statement.
These findings have been published in the International Journal of Engineering Systems Modelling and Simulation.