New research has found a link between an elevated infant death rate and mothers who are grieving over the death of a loved one in the months before conception.
“Our findings suggest that the six-month period prior to pregnancy may be a sensitive developmental period with implications for early offspring mortality,” said Quetzal A. Class, Ph.D., who led the study when she was a doctoral student at Indiana University. She is now a postdoctoral researcher at the University of Chicago.
However, the study also found that a mother’s bereavement during pregnancy doesn’t affect the infant mortality rate.
For the study, researchers analyzed data from the Danish birth registry of all women who gave birth in Denmark between 1979 and 2009.
Infant and child mortality rates were compared for women with and without “maternal bereavement” — defined as the death of a parent, sibling, or previously born child — in the months before conception or during pregnancy.
The analysis included data on nearly 1.9 million births. Overall mortality rates were 0.004 percent during the first month of life, 0.002 percent between one month and one year, and 0.001 percent between one and five years, the researcher reports.
The results of the analysis showed increased mortality for infants born to mothers who experienced the death of a family member in the months before conception.
After adjusting for other factors, the risk of infant death during the newborn period (before one month) was more than 80 percent higher for women with preconception bereavement, the study found.
For infant death between one month and one year, risk was about 50 percent higher for women with bereavement before conception. The associations were weakened — but still significant — after further adjustment for gestational age and birth weight, the researcher added.
The increases in infant mortality were significant only between zero and six months before conception, according to the analysis.
Preconception bereavement had no effect on the risk of child death between the ages of one and five.
Additionally, bereavement during pregnancy was unrelated to infant or child mortality, the research found.
“Bereavement is a major life stressor from both a psychological and physiological perspective,” Class said in the study, which was published in Psychosomatic Medicine: Journal of Biobehavioral Medicine, the official journal of the American Psychosomatic Society.
“Grieving may lead to changes in the maternal stress system affecting offspring development — particularly during the vulnerable period of early organ development — or alter the mother’s biological preparedness for pregnancy.
“This study emphasizes that the preconception period should not be overlooked when it comes to promoting infant health,” she said.