A study found that overdue babies, those who were born after 42 weeks, were more likely to suffer behavioral problems such as ADHD in early life.
Women should be aware of the risks of prolonging pregnancy, experts report in the International Journal of Epidemiology.
The research was carried out in The Netherlands, where until recently it was commonplace for women to choose not to be induced if they were overdue.
A study of more than 5,000 babies found those born after 42 weeks were more likely to develop behavioral problems than those born around their due date, and had more than twice the risk of Attention Deficit/Hyperactivity Disorder (ADHD).
Lead researcher Dr. Hanan El Marroun from the Department of Child and Adolescent Psychiatry at Erasmus MC-Sophia in Rotterdam said post-term as well as pre-term births seemed to be associated with long-term health effects.
She said: “Every pregnant woman knows that if the child comes early that’s not good, so why don’t we question the long-term effects of when a child comes too late?”
Complications include a higher risk of stillbirth and difficulties in delivering large babies.
However, a minority of women, dubbed “the 10-month mamas”, believe a baby will come in its own time and avoid medical intervention.