Can maternal stress in pregnancy affect child's motor development?

Women who experience a lot of stress in pregnancy may have children who are at risk for poorer motor development outcomes.

Stress has been implicated in a number of adverse health outcomes, but a new study suggests that stress encountered by mothers during pregnancy could affect their child's motor development all the way through to adolescence.

The study, conducted by researchers at the University of Notre Dame Australia and the Telethon Kids Institute, is published in the journal Child Development.

Previous studies have shown certain risks for offspring linked to maternal stress in pregnancy; everything from increased risk for dental cavities to increased asthma risk has been suggested.

But until now, very few studies have analyzed the link between maternal stress in pregnancy and children's motor development.

To further investigate this topic, the researchers conducted a longitudinal study that followed around 2,900 Australian mothers who were primarily white.

At 18 weeks pregnant, the women completed a questionnaire about stressful events during their pregnancies, which included financial difficulties, losing a friend or relative, separation or divorce, marital problems, pregnancy problems, losing a job or moving.

Then, at 34 weeks pregnant, the women completed the same questionnaire again.

'Accumulative effect of stress on fetal motor system'

Fast forward to when the women's children were 10, 14 and 17 years old, the researchers assessed their overall motor development and coordination with a movement test. This test checked:

§  hand strength

§  ability to touch a finger to their nose and then back to the index finger

§  distance jump

§  heel-toe walking along a line, and

§  standing on one foot.

Additionally, the researchers checked the children's fine motor skills by assessing their ability to: move small beads from one box to another, thread beads onto a rod, tap their finger for 10 seconds, turn a nut on a bolt and slide a rod along a bar.

The researchers grouped the children into three groups: those whose mothers experienced no stress during pregnancy, those whose mothers experienced fewer than three stressful events and those whose moms experienced three or more stressful events during pregnancy.

Results showed that the kids born to mothers who experienced the most stress in pregnancy had the lowest scores on motor development during all 3 survey years. The researchers say this suggests an "accumulative effect of stress on the developing fetal motor system."

What is more, the greatest observed differences in motor development were between the children whose mothers experienced no stress and those who experienced the most stress.

Cerebellar cortex development implicated

Interestingly, the researchers found that stressful events experienced by the mothers in later pregnancy appeared to have more influence on the child's motor development scores, compared with those whose mothers experienced the stress earlier.

The team says this may be down to the development of the cerebellar cortex, which is a brain area that develops later in pregnancy and controls many motor functions.

Commenting on their findings, study coauthor Prof. Beth Hands, from the University of Notre Dame Australia, says:

"Given our findings on the importance of mothers' emotional and mental health on a wide range of developmental and health outcomes, programs aimed at detecting and reducing maternal stress during pregnancy may alert parents and health professionals to potential difficulties and improve the long-term outcomes for these children."

She and her colleagues add that because low motor development has been linked to worse mental and physical outcomes, it is important to investigate early risk factors to facilitate early intervention.

"Pregnant women who are under stress could be counseled about cost-effective stress-reduction techniques such as gentle exercise," says coauthor Tegan Grace, PhD.

Although children with low motor ability can have difficulty writing, throwing and running, the researchers add that this can be improved in many cases with intervention and support.

In June of this year, Medical News Today reported on a study that suggested stress in pregnancy alters the vaginal microbiome, affecting offspring gut microbiome and brain development.