FOOD and oxygen pass easily from mother to fetus. Now it seems that fleeting sadness or happiness is also transmitted to an unborn baby.
Stress or depression in pregnancy can harm a fetus, but less is known about the effect of transient emotions. To investigate, Kazuyuki Shinohara and colleagues at Nagasaki University in Japan showed 10 pregnant volunteers a cheery 5-minute clip from the musical The Sound of Music. Another 14 watched a tear-jerking 5 minutes from The Champ. Each clip was sandwiched between two “neutral” samples so that the team could measure any changes in fetal movements against a baseline.
The women listened to the films through headphones to ensure that only the effect of their emotions, not the sounds, were being measured. “Fetuses can hear by the last trimester,” says Shinohara.
The team counted the number of arm, leg and whole body movements via ultrasound and found that during the happy film clip the fetuses moved their arms significantly more than when the pregnant women watched a neutral clip. Meanwhile, the fetuses of sad women moved their arms less (The Journal of Physiological Sciences, DOI: 10.1007/s12576-010-0087-x).
What makes the fetuses of happy mothers wave isn’t clear. However, such movement is an indicator of a working nervous, cardiovascular and musculoskeletal system, says Alexander Heazell at the University of Manchester, UK. He says the study offers us insight into how external influences affect fetuses.
Shinohara suggests that sadness releases more of the “fight or flight” hormone, which redirects blood away from the uterus. The fetus diverts the reduced blood supply to its brain and heart and away from its limbs. But Janet DiPietro of the Johns Hopkins Bloomberg School of Public Health says it’s too early to use the study to advise women.