New York, Jan 12 (IANS): Expecting mothers, stop worrying or taking any kind of stress as it may affect your baby's chance of developing disease, a new study suggests.

According to a study, published in the journal scholarly journal Biological Psychiatry, stress on an expectant mother could affect her baby's chance of developing disease -- perhaps even over the course of the child's life.

Psychosocial factors creating stress -- such as lack of social support, loneliness, marriage status or bereavement -- may be mutating their child's mitochondrial DNA and could be a precursor to a host of diseases, the researchers at the University of Cincinnati in the US said.

"There are a lot of conditions that start in childhood that have ties to mitochondrial dysfunction including asthma, obesity, attention deficit hyperactivity disorder and autism," said the lead researcher, Kelly Brunst, Assistant professor at the varsity.

"The fetal and infant period is a vulnerable time for environmental exposure due to heightened development during these periods," Brunst added.

For the study, the researchers sequenced the mitochondrial genome and identified mutations in 365 placenta samples from birth mothers.

A multivariable regression model was used to look at maternal lifetime stress in relation to the number of gene mutations in the placenta mitochondrial genome.

Women experiencing increased psychosocial stress -- that can range from sexual assault, domestic violence or serious injury to incarceration, physical or mental illness and family hardship -- over their lifetime exhibited a higher number of placental mitochondrial mutations.