Restless Legs Syndrome in Pregnant Thai Women: Prevalence, Predictive Factors, and Natural Course

Background and Purpose Restless legs syndrome (RLS) is a common sleep-related neurological disorder that affects the quality of sleep. This study aimed to estimate the prevalence, predictive factors, and natural course of RLS, and its effect on sleep quality in pregnant Thai women. Methods A cross-sectional study that included 214 pregnant women was performed. RLS was diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). General demographic and antenatal-care data were reviewed. Scores on the Thai versions of the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index, and the IRLSSG Rating Scale were determined. Results RLS was diagnosed in 24 of the pregnant women (11.2%): 4.2%, 25.0%, and 70.8% in the first, second, and third trimesters, respectively. Multiple logistic regression analysis revealed that a hemoglobin level (Hb) less than 11 g/dL [odds ratio (OR)=3.21, 95% CI=1.27-8.13] and a history of RLS (OR=16.62, 95% CI=1.52-181.32) were associated with RLS during pregnancy. Subjects with RLS significantly had higher Thai-ESS scores (p<0.01). All subjects with RLS had severe symptoms that subsided within 1 week after delivery. No immediate labor complication was associated with RLS. Conclusions Our study has confirmed a high prevalence of RLS and its impacts on sleep in pregnant women. An Hb of less than 11 g/dL and a history of RLS are predictive factors for RLS developing during pregnancy. Pregnancy-related RLS has a benign course and usually disappears within 1 week after delivery.