Published: 10-12-2013 14:22 | Updated: 10-02-2014 21:18

First-time mothers in risk zone even before 35

New research from Karolinska Institutet shows that the risk of giving birth to your first child in advanced years increase as early as in the 30-34 age group. Previously, first-time mothers were categorised as being in advanced years from the age 35. The results, which are based on the Swedish and Norwegian medical birth registers, have been presented in the scientific journal Obstetrics and Gynecology.

Women in the world's richest countries are giving birth later in life. This leads to an increased risk of preterm birth, impeded growth in the child and stillbirth, compared with women who give birth at a younger age. In the newly published study, researchers from Karolinska Institutet in Sweden and the University in Bergen, Norway looked at data from around one million first-time mothers in Sweden and Norway. Serious pregnancy outcomes in first-time mothers over the age of 30 have been compared with those aged 25 to 29.

The results show that mothers run the risk of giving birth very prematurely (pregnancy weeks 22-31) or having a stillbirth as early as in the age 30-34 age group. Previously, first-time mothers in this age group were not normally seen as a risk group. Other factors that significantly increase the risk of serious pregnancy outcomes are smoking and overweight or obesity. The risks for preterm birth, stillbirth and neonatal mortality were comparable with the risks for these lifestyle factors from the age of 35-39.

"We were surprised that the risk for certain outcomes increased at such a relatively early age. For women individually, the risk is small, but for society at large there will be a significant number of 'unnecessary' complications with so many women having children just after 30. It would therefore be advisable to inform both women and men, even at schools, of how important age is to child birth," says Ulla Waldenström, professor at the Department of Women's and Children's Health at Karolinska Institutet.

The research team will now be looking at the possible consequences of giving birth to your second or third child in advanced years. Most of the existing research is on first-time mothers in advanced years. A registry based on 2.2 million women will be analysed. The study was funded by the Swedish Research Council and the Stockholm County Council.


Adverse Pregnancy Outcomes Related to Advanced Maternal Age Compared With Smoking and Being Overweight
Ulla Waldenström, Vigdis Aasheim, Anne Britt Vika Nilsen, Svein Rasmussen, Hans Järnbert Pettersson, Erica Shytt
Obstetrics and Gynecology, online 6 december 2013