Although pregnancy and sex hormone therapy are known to influence the multiple sclerosis (MS) relapse rate, researchers have now found that women with MS are more likely to relapse if they undergo in vitro fertilization (IVF).

Women are significantly more likely to develop MS than men and results from the study, published online in the Journal of Neurology Neurosurgery and Psychiatry, indicate that hormones may play a role in MS.

The researchers set out to determine whether synthetic hormonal treatments used during assisted reproduction techniques might influence the relapse rate among women with MS.

The team examined 32 women with MS who underwent IVF between 1998 and 2008 at 13 French university hospitals.

In total, 70 cycles of IVF were carried out, of which 19 included gonadotrophin releasing hormone (GnRH) antagonists, and 48 GnRH agonists. These chemicals are designed to regulate the timing of the release of natural hormones needed to prompt the ovaries and womb to prepare for a pregnancy.

The researchers found that women were considerably (60%) more likely to suffer a relapse in the three months after IVF treatment. In the three months after the 70 IVF procedures, 26 relapses occurred.

This figure increase to 71% when the time frame was reduce to two months. IVF failure and GnRH agonists both increased the risk of relapse, rather than antagonists.

The risk of relapse in the three months after treatment was 50% higher among the women who failed to get pregnant with IVF. 40% of women got pregnant with GnRH agonists vs 10% of women treated with GnRH antagonists.

According to the researchers, the stress of IVF could increase the risk of relapse, and may explain some of their findings. However, women suffering from MS who undergo IVF should be informed of the potential increase risk of relapse, particularly if the treatment does not result in pregnancy.

Written By Grace Rattue