15–25% of pregnant women have RLS in Western countries according to prevalence studies (Lee et al., 2001; Neau et al., 2010). A peak prevalence of RLS in pregnant women mainly occurred in the third trimester and gained a remission by 1 month after delivery (Ismailogullari et al., 2010). Surveys manifested that nulliparous women were at the same risk of RLS as same aged men, while the risk for women were increased after one pregnancy (OR 1.98) and two pregnancies (OR 3.04), even more after three or more pregnancies (OR 3.57) (Berger et al., 2004; Pantaleo et al., 2010). These findings may explain the gender difference in RLS prevalence. The reason why pregnant women have higher risk of having RLS remains unknown. One reason is that an increased demand of iron in pregnant women results in relative iron deficiency. The other established factors included hormonal status (prolactin, progesterone and estrogen), folate deficiency and stretch or compression of nerves due to fetal growth conflicting (Pantaleo et al., 2010; Pereira et al., 2013). Psychomotor behavioral change during the last weeks of pregnancy might also contribute to the symptoms. Anxiety, insomnia, and fatigue are always associated with pregnancy in the last trimester.