Unborn Babies’ Heart Rhythms Become Steadier After Listening to Classical Music, Study Finds

Written by Chantal Gapato  |  November 5, 2025

Study in Mexico finds unborn babies’ heart rhythms become steadier after listening to classical music

Researchers in Mexico have discovered that classical music can influence how unborn babies’ hearts behave. In the study, 37 healthy fetuses between 32 and 40 weeks of pregnancy were monitored before, during, and after hearing two short pieces of classical music. The scientists analyzed not only the heart rate but also the tiny differences between beats, using a technique called recurrence plot analysis to understand how regular or complex the heartbeat patterns were.

After the music exposure, the fetuses’ heart rhythms became more regular and predictable. Measures linked to rhythm stability, such as determinism and line length, increased, while randomness, known as entropy, decreased. Although the overall variability in heart rate stayed about the same, the rhythm itself appeared more coordinated and steadier. The results suggest that classical music may have a short-term calming or organizing effect on the fetal nervous system, showing that even before birth, babies can respond to external sounds in measurable ways.

The researchers noted that their findings are limited to healthy pregnancies late in gestation and to short-term exposure to classical music. They also cautioned that while the results show a physiological response, they do not necessarily indicate any long-term developmental effects. The study was conducted in Toluca, Mexico.

Read the full study here: Response to music on the nonlinear dynamics of human fetal heart rate fluctuations: A recurrence plot analysis (2025).