Maternal stress during the second trimester of pregnancy can affect the developing nerve system of the fetus, both before and after delivery, with consequent effects on the personality of the child, such as less ability to regulate emotions.
This conclusion results in an American study published in the scientific paper Development and Psychopathology. Researchers at the University of California, San Francisco, looked at the low-to-moderate levels of anxiety of 151 women who lived between the 12th and the 24th week of pregnancy.
Scientists watched women throughout pregnancy and postpartum and compared their reported levels of anxiety during pregnancy to the observed levels of anxiety in the newborn when it was six months old. In particular, the baby’s heart rate was recorded while the mothers looked at the face for interaction or were resting for two minutes after they had been playing for a while with them.
Mothers reported the number of stressful events they had experienced during pregnancy, such as illness, relationship problems, legal issues and home difficulties. Mothers with the highest number of stressful events were 22% more reactive than those of women who reported the smallest number of stressful events.
“The high reactivity that depicted in high heart rate fluctuations coupled with respiratory rate is indicative of a greater reduction in parasympathetic nervous system activity in a challenge,” explains the lead author of the study, Dr. Nicolas Bush.
The parasympathetic nervous system gives the body the ability to rest and contributes to digesting food, slowing down heartbeat while increasing the activity of the glands and the gastrointestinal system.
“This is not automatically good or bad, but it is known that children are at risk of various psychopathological problems, namely anxiety and depression, as well as disruptive behavior, especially if they have lived in negative family and school environments.”
Finally, the questionnaires completed by 151 mothers showed that those with the highest levels of anxiety in pregnancy and postpartum had acquired children with lower levels of mood for approaching and interacting with the outside environment as well as laughing or smiling. They also had lower levels of self-regulation, ability to control their feelings, compared to children born to mothers with less stress during and after pregnancy.