Fetal heart rate monitoring during the second half of pregnancy can help veterinarians easily and reliably assess the health of the unborn foal, according to new research by German and Austrian veterinary scientists. However, it’s unlikely to give clues about when a mare will foal.

Fetomaternal electrocardiogram (ECG) equipment, with filtering to enhance the fetal heart recordings, can consistently detect the cardiac activity of unborn foals from day 173 (of 340 gestational days) onwards, reported Christina Nagel, MSc, PhD candidate at the Graf Lehndorff Institute for Equine Science in Neustadt (Germany) and primary researcher in the study. In the scope of her study, the fetal heart rate could almost always be found within the first ten minutes.

"Fetal ECG is an important tool, in addition to transrectal or transabdominal ultrasounds, for monitoring high-risk pregnancies and assessing their potential outcomes," said Christine Aurich, DVM, PhD, professor at the Graf Lehndorff Institute and at the University of Veterinary Sciences in Vienna and co-author of the study.

It can also be used to determine whether a fetus has died, which is difficult to determine via ultrasound alone, she added