Obese and overweight women can successfully conceive through fertility treatment as normal weight women, according to a new Scottish study.
Study leader Dr Abha Maheshwari, clinical lecturer in reproductive medicine at the University of Aberdeen insists that obese women should not be declined treatment solely on size.
But should be advised to lose weight because of the high risk of complications.
Most primary care trusts limit IVF to women with a body mass index under 30, which excludes women classed as obese.
In the study involving 1,700 women who underwent their first cycle of IVF between 1997 and 2006 in Aberdeen, the researchers found that 28pct were overweight, 8pct were obese and 5pct had a BMI over 35 - classified as heavily obese.
However, they found no significant difference between groups in the proportion of women having a positive pregnancy test, ongoing pregnancy, and live birth.
Moreover, there was no difference in the cost of a live birth between normal weight women and women with a BMI up to 35.
"It shows that age is a more important factor than weight," the BBC quoted Maheshwari as saying.
The study showed that higher proportion of women in the overweight or obese groups still had miscarriage, and they required higher doses of drugs used to stimulate the ovaries.
"Everybody should be encouraged to lose weight, but treatment shouldn't be declined on weight alone," she added.
But she said that women with a BMI over 35 should not be offered IVF until they lose weight particularly due to high complications risk.