Study Suggests Classical Music Results in More Stable Fetal Heart Rate

Researchers from Mexico found that exposure to classical music can improve heart rate variability, a key indicator of healthy autonomic nervous system development

A study undertaken by researchers from the Autonomous University of the State of Mexico, the Metropolitan Autonomous University, the General Hospital Nicolás San Juan, and the National Institute of Cardiology Ignacio Chávez has explored the effects that playing classical music may have on fetuses in the womb.

In particular, the study looked at the effects of classical music on heart rate variability — which measures the time between individual beats. Heart rate variability is an important measure because it can provide insight into the maturation of the fetal autonomic nervous system, with more variability indicating healthy development.

Researchers looked at the effects of music of differing styles, contrasting Saint-Saëns's "The Swan" with the rhythmical guitar work "Arpa de Oro" by the Mexican composer Abundio Martínez. They measured the fetal heart rate throughout, and then used mathematical analysis tools to identify changes in heart rate variability during and after the music was played.

"Overall, we discovered that exposure to music resulted in more stable and predictable fetal heart rate patterns," said author Claudia Lerma. "We speculate that this momentary effect could stimulate the development of the fetal autonomic nervous system.

"We did notice some significant differences [between the two pieces]," said author Eric Alonso Abarca-Castro. "In particular, the second piece appeared to have a stronger impact on some measures, indicating that it produced heart rate patterns that were more predictable and regular. Factors like rhythmic characteristics, melodic structure, or cultural familiarity may be linked to this differentiation."

"Our results suggest that these changes in fetal heart rate dynamics occur instantly in short-term fluctuations, so parents might want to consider exposing their fetuses to quiet music," said Abarca-Castro. "Parents who play soothing music may stimulate and benefit the fetal autonomic system."

"To ascertain whether rhythmic or cultural variations elicit distinct fetal cardiac responses, we intend to increase the size of our sample and expand our investigation to include a variety of musical styles beyond classical pieces," said author José Javier Reyes-Lagos.