(RxWiki News) The effects of a mother's body on her developing child are still mysterious in many ways. For example, the possible effects of emotional stress on a baby aren't totally understood.
A recent study attempted to understand this impact a little better. Researchers looked at the rate of heart defects among babies whose mothers had lost a loved one within a year of conceiving their child.
Then they compared this rate to the rate in babies whose mothers had not lost a loved one. The researchers found a link, but it was a weak one.
Mothers who had lost a loved one were only slightly more likely to have babies with heart defects, and other factors could have played a part.
"Talk to your obstetrician if you're depressed while pregnant."
The study, led by Jin Liang Zhu, PhD, of the Research Programme for Children’s Mental Health at Aarhus University in Denmark, investigated whether a mother's grief around the time of conception had any link to her baby's risk for heart defects.
The researchers first looked at the records of all 1.8 million single baby births in Denmark between 1978 and 2009. Within this group, 44,820 children had been born to mothers who had lost a close relative within one year of having conceived their child.
Among these women, 6,080 had lost their romantic partner or a child, and 38,740 women had lost a sibling or one of their parents.
The researchers then compared the rates of congenital heart defects among the children born to moms who had lost someone and the children born to moms who had not.
The researchers adjusted their calculations to account for the baby's sex and date of birth, the mother's age when she gave birth, the family's socioeconomic factors and how many children the mother already had.
They also took into account whether the mothers smoked or had diabetes and whether either parent or a sibling had had a birth defect.
In general, the researchers found that the women who had lost a close family member were more likely to be older, to already have had children and to have been smokers.
Among all the children born, 14,507 (0.82 percent) had a heart defect.
The researchers found that 94 of every 10,000 children born to mothers who had suffered a loss had a congenital heart defect. Meanwhile, 82 of every 10,000 children born to mothers who had not experienced a loss had a congenital heart defect.
An analysis of these results revealed that children of mothers who had grieved within a year of conception were very slightly more likely to have had a heart birth defect.
The link was very small: babies born to mothers who had lost someone were only 11 percent more likely to have a heart defect than babies born to mothers who had not lost someone.
The risk was very slightly higher among children whose mothers had lost a child or partner. Those children were 15 percent more likely to have a congenital heart defect. The rate among these children was 115 babies with heart defects out of every 10,000 born.
One finding that surprised the researchers was that the risk of having a baby with a heart defect was slightly higher among women whose loss was expected rather than unexpected.
In other words, women who lost a spouse, child, parent or sibling to a cause of death they knew about in advance had a higher risk than women who lost a loved one unexpectedly.
However, this finding relied on such small numbers of babies and mothers that it is possible it occurred only by chance.
The researchers concluded that a baby's "prenatal exposure to severe emotional stress may slightly increase" the likelihood of having a heart birth defect.
However, the association was very small, and the researchers were relying on the experience of losing a loved one to substitute for "severe emotional stress."
The researchers were not able to take into account other forms of stress that any of the mothers may have experienced. They also did not speak to the mothers to determine how well or how poorly the women had handled the deaths of loved ones.
The study was published March 25 in the journal Pediatrics. The research was funded by the European Research Council, the Danish Medical Research Council and the Tryg Foundation. The authors declared no conflicts of interest.