Research suggests that restless legs syndrome (RLS) is associated with pregnancy and delivery complications — but specific details on how the disorder affects pregnant women are scarce. This led researchers to further study the role of RLS and its frequency with sleep-wake disturbances during pregnancy. Their findings were published in the Journal of Clinical Sleep Medicine in 2017.
The study’s authors pointed out that RLS affects as many as one in three pregnant women (compared to a prevalence rate of just one in 20 of the global population), typically peaks in the third trimester, and usually subsides after delivery. It’s thought that pregnant women are more likely to experience RLS due to hormonal changes, iron and folate metabolism, and changes in blood flow.
To investigate RLS in pregnant women, researchers recruited 1,563 women during their third trimester of pregnancy. The presence of RLS was measured using the Brief Restless Legs Scale — a questionnaire that asks the following questions:
Do you have unpleasant sensations in your legs combined with the need to move your legs?
Do these feelings occur mainly or only at rest and do they improve with movement?
Are these feelings worse in the evening or night than in the morning?
How often do these feelings occur?
Women who answered “yes” to the first three questions were determined to be experiencing RLS. The fourth question was used to gauge RLS frequency, with women divided into four groups based on how often they experienced RLS symptoms.
Sleep quality and daytime function was measured using the General Sleep Disturbance Scale, while daytime sleepiness was measured using the Epworth Sleepiness Scale. Women were also asked whether or not they habitually snored (defined as snoring at least three nights per week).
Demographic and pregnancy characteristics were also extracted from medical records. That information included:
- Prepregnancy body mass index (BMI)
- Gestational weight gain
- Number of prior successful pregnancies
- Health problems such as high blood pressure and diabetes
- Delivery outcomes
RLS during pregnancy
Researchers found that 36 percent of pregnant women had RLS. Most were white, had given birth before, and reported poor sleep quality and poor daytime function. One in three women with RLS reported the presence of all three measured sleep disturbances (poor sleep, poor daytime function, and sleepiness).
Two-thirds of women with RLS reported the occurrence of symptoms at least twice each week, while one-quarter experienced symptoms at least four times each week. Perhaps unsurprisingly, the study found that as RLS frequency increased, so did the odds for sleep-wake disturbances such as:
- Difficulty falling asleep
- Difficulty staying asleep
- Nighttime awakenings
- Insufficient sleep
- Daytime fatigue
When researchers compared pregnant women without RLS, those with RLS were more than twice as likely to have poor sleep quality and had significantly increased odds for poor daytime function or excessive daytime sleepiness.
No significant differences in prepregnancy BMI, habitual snoring, high blood pressure, or diabetes were found between women with and without RLS. Additionally, no association was found between RLS and delivery outcomes.
The importance of RLS screening during pregnancy
The authors of the study concluded that due to the high prevalence of severe RLS during pregnancy, obstetric health care providers should screen for its presence. Furthermore, since RLS can have significant effects on sleep quality and daytime functioning, symptom management is of particular importance during pregnancy.
Recommended treatment approaches for RLS during pregnancy include:
- Moderate exercise
- Iron supplements
- Avoiding alcohol and caffeine
- Elastic stockings or pneumatic compression devices (PCDs)
If you are pregnant, or planning to become pregnant, you are more likely to experience RLS — and this can have a negative impact on your sleep and your daytime function. If you recognize RLS symptoms such as an aching or creepy-crawly sensation in your legs, speak with your doctor so you can take steps to improve your sleep during pregnancy.
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Martin is the creator of Insomnia Land’s free insomnia sleep training. His online course uses CBT techniques to teach participants how to sleep better without relying on sleeping pills. More than 5,000 insomniacs have completed his course and 97 percent of graduates say they would recommend it to a friend.