Both need reliable and accurate monitoring to provide sufficient data for making informed decisions.
The reality of having one patient inside the other creates a unique but common problem: heartbeat coincidence (HBC). This occurs when the fetal heart rate value displayed on the monitor originates from the maternal heart source or in multiple gestations, the fetal heart rate from one fetus mimics another fetus.
Discerning the maternal heart rate vs. fetal heart rate (or fetal vs. fetal) is key to making the appropriate care decisions. Adult and fetal hearts generally beat at different rates, allowing providers to distinguish whose cardiac activity is whose on the monitor. However, factors such as the baby's position or abnormal heart rates for either patient can cause HBC.
Especially in HBC situations with maternal tachycardia where the maternal heart rate is in a normal fetal heart rate range, fetal compromise can be masked and therefore be left untreated if not recognized by the clinician.
Detecting Maternal Fetal HBC in the Most Critical Moments
To effectively rule out confusion between heart rates, it is important to measure a maternal pulse to recognize when two separate heartbeats might be in coincidence.
Monitoring technology provides reassurance when there are positive indicators of fetal oxygenation, such as moderate fetal heart rate variability or accelerations. The interpretation can be less clear when there are potential indicators of a problem, such as decreased fetal heart rate variability, fetal heart rate decelerations, or maternal tachycardia. In these cases, it's essential to promptly and accurately consider the cause(s) for these changes and intervene with protective measures, such as maternal position changes or reduced uterine activity, as per evidenced-based standards.
Dealing with heartbeat coincidence in emergency situations causes further confusion and can lead to either unnecessary interventions or a failure to intervene promptly. In these moments, considering clinical context, drawing on bedside observation with frequent assessments, and having reliable monitoring tools can be life-saving.
Patented Algorithm for a Unique Way to Detect HBC
Clinicians should take advantage of all available maternal-fetal monitoring tools to reliably distinguish two heartbeats. Getting a baseline of the maternal heart rate with pulse oximetry—or simply palpating the mom's wrist to determine the birthing parent's pulse—is the first step to distinguishing maternal heart rate vs. fetal heart rate.
Doppler ultrasound is widely used, yet its accuracy is affected by many variables including maternal and fetal positioning, and it is plagued by high rates of heartbeat coincidence. Electrocardiogram (ECG)-based fetal heart monitoring through fetal scalp electrode is more reliable but is limited in use due to its invasive design.
The GE Corometrics maternal-fetal monitor unique HBC algorithm uses a patented method to detect heartbeat coincidence. Instead of just comparing the actual rates which can trigger false positives, the GE HBC detection uses the raw signals and looks for a consistent relationship between the phases of the two heart rates.
"We look at it from a heart rate and pulse relationship between two sources," says GE Healthcare Chief Engineer Steve Falk. "We can tell, probabilistically, that it's actually coming from the same source."
With prompt recognition and reliable technology, maternal-fetal heartbeat coincidence can be readily identified and the appropriate interventions considered.
Novii Technology Lowers the Chances of Confusing Maternal and Fetal Heart Rates
The Novii abdominal patch system provides yet another way to minimize the problem by minimizing the confusion from the point of signal detection. The Novii technology measures fetal and maternal ECG, then uses amplitude, morphological differences, and R-R intervals to uniquely distinguish maternal and fetal heartbeats. This process removes nearly all maternal and fetal heartbeat coincidence. The ability to distinctly distinguish the fetal and maternal heartbeats at the source means fewer alerts because confusion between the maternal and fetal signal is 20-fold times less likely to occur, according to a study published in Acta Obstetricia et Gynecologica Scandinavica.1
Besides offering clinicians more confidence in their data, Novii provides a more comfortable and less invasive alternative to fetal scalp monitors. Instead, both heartbeats are assessed through a single abdominal patch. Its wireless connection also keeps patients untethered during labor. This is a huge advantage for patients, such as individuals with higher BMIs and more challenging to monitor with traditional methods, those whose membranes are not yet ruptured, or those who simply want to walk around or use a birthing ball.
The GE Corometrics HBC algorithm and the Novii abdominal patch system provide clinicians with unique additional tools in their monitoring toolbox to customize for their specific patient needs and provide the best data. GE's Maternal Fetal Monitors allow for clear identification and confident interpretation of the fetal and maternal heart rates.
References:
- Cohen WR, Ommani S, Hassan S, et al. Accuracy and reliability of fetal heart rate monitoring using maternal abdominal surface electrodes. Acta Obstetricia et Gynecologica Scandinavica. 2012;91(11):1306-1313. doi:10.1111/j.1600-0412.2012.01533.x
