A major claim of anti-abortion campaigners appears to have been undermined by a new study showing termination of pregnancy does not lead to mental health problems. Although women who had abortions were found to have a higher incidence of pre-existing mental health problems in a major new study relative to women who gave birth.

It is sometimes argued by opponents of abortion that the procedure can lead to psychiatric problems. Now a huge study in Denmark has failed to find a link between abortion and contact with psychiatrists. While there was a statistically significant increase in mental health problems after giving birth, there was no significant increase after abortion.

“The incidence rate of psychiatric contact was higher among girls and women who underwent an abortion than among those who underwent delivery, but this relationship was evident before the abortion or childbirth occurred,” write the team, led by Trine Munk-Olsen of Aarhus University. “On the basis of these results, it seems likely that girls and women having induced abortions constitute a population with higher psychiatric morbidity.”

The team looked through the medical records of all girls and women born in Denmark between 1962 and 1993 who were alive at age 15.

They picked out those who had no history of mental disorders 9 months before either their first abortion or their first childbirth. Of 84,620 who had a first-time, first-trimester abortion between 1995 and 2007, 1% had contact with a psychiatrist 9 months before the abortion and 1.5% had such contact 12 months after, they report in the New England Journal of Medicine.

Of the 280,930 people who gave birth to their first child, the equivalents were 0.3% before and 0.7% after. There was no statistically significant increase in risk of psychiatric contact after an abortion but the risk was significantly greater after giving birth.