New Fetal Heart Monitor Could Save Lives
A new simple yet sensitive fetal heart monitor could save the lives of unborn infants at risk of preterm delivery, miscarriage, or death. The fetal monitoring system allows expectant mothers to transmit critical information about their infant to their physician and to themselves using a common personal computer.
According to the latest figures from the National Center for Health Statistics, 12.5 percent of all pregnancies in the United States deliver prematurely, which is defined as giving birth before 37 weeks’ gestation. Two percent of all deliveries occur at less than 32 weeks’ gestation, 5.5 percent between 32 and 35 weeks, and 4.2 percent at 36 to 37 weeks. Currently clinicians utilize various forms of fetal monitoring, including ultrasound, to identify problems in complex pregnancies.
Disturbances in fetal heart rate are best monitored over time and not with a “snapshot” approach, such as ultrasound provides. Although frequent ultrasound monitoring can be done, it is not convenient nor recommended. The new fetal heart monitoring system allows clinicians to gather continuous information about the infant’s heart rate. It consists of two microphones, one of which is attached to the mother’s abdomen and the second is placed a reasonable distance away to detect ambient and bodily noise. Information from the two microphones is transmitted to a wave analyzer in an Internet-connected personal computer that the pregnant woman keeps by the bedside.
Specialized software can eliminate the ambient noise from the fetal heart rate sounds to produce a file that can be evaluated for abnormalities. If the system detects a problem with the fetal heart rate, it can quickly send a report to the physician’s computer or warn the pregnant women to seek medical assistance.
A serious decline in fetal heart rate typically occurs at night around the time the pregnant woman is ready to go to sleep. This is when the woman’s heart rate and blood pressure drop, and in infants at risk, an abnormality in fetal heart rate can occur as well. Thus use of the fetal heart monitoring system at bedtime and during the night is the best time to detect and track any abnormalities in fetal heart rate.
The new fetal heart rate monitoring system is inexpensive, easy to use, and unlike ultrasound and sonograms, does not involve sending any energy into the woman’s womb. Thus far the monitoring system has proved successful in women at various stages of pregnancy.
Martin JA et al. National Vital Statistics Reports; 55(1): National Center for Health Statistics 2006
Mittra AK et al. International Journal of Engineering Systems Modelling and Simulation 2009; 1:92-100