STRESS does not affect a woman's chance of getting pregnant with IVF, research has concluded.

Doctors from Cardiff University in Britain examined 14 studies involving 3583 infertile women undergoing fertility treatment to see if anxiety levels and depression measured before treatment were linked to the outcome of a successful pregnancy or not. No link was found between the two factors.

A report on the research published in the British Medical Journal yesterday said although many women believed emotional distress contributed to their infertility and lack of success with treatment, this review showed it was not the case. The authors also noted that it debunked the fertility myth that relaxed women conceived more easily than other women.

''This [allows] doctors to reassure women that feelings of tension, worry or depression experienced as a result of their fertility problem, its treatment, or other co-occurring life events are unlikely to further reduce their chance of pregnancy,'' the authors wrote.

However, they said more should be done to help couples through infertility treatment because it was often arduous, causing about a third of people to drop out prematurely.

A cycle of IVF typically involves nine to 12 days of self-injection to stimulate egg production, followed by retrieval of eggs, fertilisation of those eggs with sperm, and then implantation of the embryo into the woman's uterus.

According to the Fertility Society of Australia, about one in six Australian couples experience infertility and about 10,000 IVF babies are born each year in Australia.