What should fhr be

FHR decreases slightly during gestation. Normal ranges for FHR are to bpm. Many international guidelines define ranges of to bpm which seem to be safe in daily practice. The results about the normal range are very robust, indicating that neither the type of hospital which is potentially linked to special selection criteria for the pregnant women nor the time as measured roughly in 5—10 year intervals seems to play a role — an argument for the external validity of the findings in the exploratory part.

For user acceptance we used steps of 5 bpm as possible borders of the normal FHR as recommended in the consensus meeting of the National Institute of Child Health and Human Development Macones et al. The width of the interval of 40 to 45 bpm was traditionally used in many international guidelines. As we planned the study, we chose no other intervals, as narrowing of the interval would increase the false alarm rate and wider intervals could miss pathologic conditions of the fetus.

It could be shown that the current FIGO guidelines based on computerized analyses of the CTG show a high sensitivity to detect fetal acidosis in case of a suspect or pathological classification of the baseline level. It may turn out that a modification of the normal ranges further improves sensitivity and specificity of fetal acidosis during labor Schiermeier et al. Also, multivariate modeling involving fetal and maternal outcome data may improve evidence-based online decision support tools.

Data from a recently published study in a different context Serra et al. Data for the 97th and 99th percentiles are not shown in this study. But shifting the lower limit to will increase the number of false alarms whereas a lower limit of will inevitably increase the risk to misinterpret maternal heart rates as fetal heart rate. This last problem has raised many concerns and discussions about technical solutions for differentiation of maternal and fetal heart rate, as fatal consequences for the fetus could occur Murray, As FHR tracings of prenatal care patients were included, our study population consists of a fraction of pregnancies remote from term, eventually resulting in higher baselines as suggested before.

As our analysis according to gestational ages shows, the upper limit of bpm is valid for younger and for later gestational ages. A lower limit of bpm leads only near term to more false alarms since normal FHR decreases further, and is more appropriate, as discussed above, to avoid misinterpretation of maternal heart beat as FHR. There are no different guidelines for scoring cardiotocograms of early gestational ages as this would be too difficult in daily practice.

Only computerized algorithms could use boundaries without rounding based on multivariate modeling and correlate these results to fetal outcome. FIGO guidelines defined boundaries from to bpm, representing the approximately 0. We raised concerns about the broad width of the range of 50 bpm and the lower limit of bpm.

As these guidelines are in use for some years in many countries at the moment, we assume that this range is still safe for detection of fetal compromise. In contrast, specificity of the CTG for fetal acidosis becomes better. But safety-analyses should confirm this assumption. Fahrmeir, Ludwig-Maximilians University, for continuous support. The comments of Marlene Sinclair and another anonymous reviewer have helped to further improve the manuscript.

Trium is a manufacturer of CTG monitoring systems. There is no known financial or other conflict of interests for the other authors. Author Contributions Stephanie Pildner von Steinburg conceived and designed the experiments, performed the experiments, analyzed the data, wrote the paper.

Sven Schiermeier performed the experiments, analyzed the data, wrote the paper. Wolfgang Hatzmann performed the experiments, and critical review of mansucript. Karl-Theodor M. Schneider conceived and designed the experiments, performed the experiments, and critical review of manuscript.

Human Ethics The following information was supplied relating to ethical approvals i. Patent Disclosures The following patent dependencies were disclosed by the authors:. National Center for Biotechnology Information , U. Journal List PeerJ v. Published online Jun 4. Schneider , 1 and Martin Daumer 2, 3. Author information Article notes Copyright and License information Disclaimer. Corresponding author. Martin Daumer: gro. Received Mar 4; Accepted May This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This article has been cited by other articles in PMC. Abstract Aim. Introduction Recording of fetal heart rate FHR via cardiotocography CTG monitoring is routinely performed as an important part of antepartum and intrapartum care. Material and Methods In order to reduce the probability of publishing false positive results, this study followed a strict analysis plan, published before onset of the analyses Daumer et al.

Formulation of the normal fetal heart rate range We considered multiples of five as candidate FHR limits. Table 1 Patient characteristics. The heart rate of a baby girl is usually faster than that of a baby boy. But this is only true after labor begins.

What are signs of having a girl? We look at the science behind eight traditional signs of having a girl: Severe morning sickness. Share on Pinterest Severe morning sickness may be a sign of having a girl. Extreme mood swings. Weight gain around the middle. Carrying the baby high. Sugar cravings. Stress levels. Oily skin and dull hair. Baby's rapid heartbeat. Is there a difference between boy and girl heartbeats?

A healthcare professional can make an educated prediction about a baby's sex during an ultrasound. Does placenta position indicate gender? The short answer is no. There've been no further studies on using placenta placement to predict sex as early as 6 weeks. Although the myocardium begins to contract rhythmically by 3 weeks after conception from spontaneously depolarizing myocardial pacemaker cells in the embryonic heart it is first visible on sonography around 6 weeks of gestation.

The FHR is then usually around to beats per minute bpm. Although in the healthy fetus the heart rate is usually regular, a beat-to-beat variation of approximately 5 to 15 beats per minute can be allowed.

A slow fetal heart rate is termed fetal bradycardia and is usually defined as 1 :. A rapid fetal heart rate is termed a fetal tachycardia and is usually defined as:. A rapid and irregular fetal heart rate is usually termed a fetal tachyarrhythmia. Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Updating… Please wait. Unable to process the form. Check for errors and try again.