Ronald M. Cyr, MD


September 01, 2010

In This Article

Fetal Heart Rate

In 1833, Evory Kennedy wrote the first systematic publication on fetal heart auscultation. In 1859, Ferdinand Frankenhauser delivered a paper before the Obstetrical Society of Berlin, suggesting that a more rapid fetal pulse (ie, an average of 144 beats/min or more) during the last trimester of pregnancy foretold that a girl would be born, whereas a rate of 124 beats/min or less signified a boy. Numerous publications on this subject appeared over the next 50 years, with inconsistent results. Perhaps the largest published study was reported by John Cyril Holdich Leicester in 1907. Working in Calcutta, he measured the fetal heart rate at term, immediately before active labor, in 550 women of various races. The findings were correlated with both the sex and weight of the newborn. His conclusions were that:

  • Sex has practically no effect on the frequency of the fetal heart beat;

  • It is impossible, in any given case, to form even a rough judgment with regard to sex using the fetal heart rate; and

  • As a general rule, weight seems to exercise a distinct influence, because the slower the fetal heart rate, the bigger the child is likely to be. However, numerous exceptions exist.[8]

Surprisingly, many clinicians and patients today seem to still believe in this relationship between sex and fetal heart rate.


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