The pregnant body is much more sensitive to its surroundings; just ask a pregnant woman in the throes of morning sickness if she wants a strong-smelling food. But now, new research shows that the effects of music are stronger in pregnant women, including greater changes in blood pressure.
The researchers - from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany - say music can affect blood pressure, heartbeat, respiration and even body temperature under normal conditions.
But its influence on pregnant women is much stronger, suggesting a prenatal conditioning of the fetus to music, they say.
Medical News Today recently reported on a study that showed brain scans of jazz musicians reveal similarities between language and music, suggesting that the brain uses its syntactic regions to process all communication, whether spoken or musical.
To conduct their study, the researchers, led by Dr. Tom Fritz, played musical sequences up to 30 seconds long to female participants.
The team modified the passages by playing them backwards or including dissonances, thus distorting the original instrumental songs and making them less pleasant to hear.
Results showed that the pregnant women rated the pleasant music as more pleasant and the unpleasant music as more unpleasant. Additionally, the blood pressure response to the music was much stronger in the pregnant women.
For example, forward-moving dissonant music prompted a significant drop in blood pressure in the pregnant women, whereas the backward-moving dissonant movement resulted in a higher blood pressure after 10 seconds and a lower one after 30 seconds.
Commenting on their findings, Dr. Fritz says:
"Thus, unpleasant music does not cause an across-the-board increase in blood pressure, unlike some other stress factors. Instead, the body's response is just as dynamic as the music itself."
'Fetuses may be conditioned to perceive music in the womb'
The results of the study suggest music is a special stimulus for pregnant women, says Dr. Fritz.
"Every acoustic manipulation of music affects blood pressure in pregnant women far more intensely than in non-pregnant women," he adds.
The research shows that pregnant women exhibit greater changes in blood pressure while listening to music.
But he and his team are unsure as to why music influences pregnant women so strongly, physiologically speaking. They hypothesized estrogen could play a role, given that it influences the reward system in the brain - which is responsible for eliciting pleasant sensations while listening to music.
Their theory was disproved, however, because the physiological responses of non-pregnant women to music remained constant throughout their reproductive cycle, even during times when their estrogen levels would have fluctuated.
Dr. Fritz concludes that either "estrogen levels are generally too low in non-pregnant women, or other physiological changes during pregnancy are responsible for this effect."
He and his team say their findings suggest that, based on the intense physiological music responses of the mothers, fetuses are conditioned to perceive music while still in the womb.
They add that, at the start of the third trimester, the fetal heart rate already begins to change when it hears a familiar song, and from 35 weeks, there is even an observed change in its movement patterns in response to familiar music.
In 2013, Medical News Today reported on a study that suggested music training in childhood boosts the brain in adulthood.