During pregnancy, one in four women will experience restless legs syndrome, Italian researchers report.

The current study is not the first to make a connection between restless legs syndrome and pregnancy. However, it is the first to base the diagnosis on the four criteria set forth by the International Restless Legs Syndrome Study Group in 1995. These include the desire to move the legs usually associated with pain or tingling sensations; restlessness in the legs; worsening of symptoms with inactivity; and worsening symptoms at night.

The findings, which appear in the medical journal Neurology, stem from a study of 642 pregnant women who were evaluated for restless legs syndrome using the recently introduced criteria.

Twenty-six percent of women had restless legs syndrome at some point during their pregnancy, lead author Dr. Mauro Manconi, from Vita-Salute University in Milan, and colleagues note. The percentage of women with restless legs syndrome rose dramatically during the third trimester, and most of the cases resolved around the time of delivery.

The only risk factor for developing restless legs syndrome during pregnancy was a low level of hemoglobin, an iron-containing molecule that allows red blood cells to carry oxygen.

Further studies are needed to determine why restless legs syndrome is so common during pregnancy, the researchers note.

SOURCE: Neurology, September 28, 2004.