Restless legs syndrome during pregnancy

By trimester

Weeks 1–13

1st trimester

Restless legs syndrome is least common this early in pregnancy. When it does show up now, it more often reflects a folate or iron picture that predates the pregnancy, so mention any earlier history of restless legs, heavy periods, or low iron at your first prenatal visit. That gives your provider useful context.

Weeks 14–27

2nd trimester

It's common for restless legs to start or get worse in the second trimester, as your blood volume expands and your need for folate and iron climbs. This is a good time to ask your provider whether checking a ferritin or folate level alongside your routine labs makes sense for you.

Weeks 28–birth

3rd trimester

Restless legs syndrome is most common and most intense in the third trimester, on top of the other physical discomforts already disrupting your sleep this late in pregnancy. Here's the reassuring part: symptoms typically ease quickly after delivery.

What does the evidence show for restless legs syndrome?

• Restless legs syndrome is two to three times more common during pregnancy than outside of it, and how often it shows up shifts by trimester and tracks closely with iron and folate levels. 1
• One study followed women from before conception through pregnancy and found that low folate levels tracked more closely with restless legs syndrome and disrupted sleep than any standard iron marker did, including ferritin, serum iron, and hemoglobin. 2
• Researchers studying what causes restless legs syndrome in pregnancy point to iron metabolism, ferritin level, folic acid status, vitamin D, and shifts in zinc and magnesium, alongside hormonal changes, as leading factors. 3
• Pregnancy raises your daily folate need to 600 mcg dietary folate equivalents, up from 400 mcg for non-pregnant adults, showing just how much more of this nutrient pregnancy demands. 4
• Pregnancy raises your daily iron need to 27 mg, up from 18 mg for non-pregnant adults, and low iron during pregnancy raises the chance of preterm birth and low birthweight, which is part of why routine screening matters. 5
• The International RLS Study Group criteria require an urge to move the legs usually accompanied by unpleasant sensations, worse at rest, partially relieved by movement, and worse in the evening or night hours, and in pregnancy-onset cases symptoms disappeared in 97 percent of women within a few days after delivery. 6

When should I call my provider about restless legs syndrome?

Pregnancy RLS should fit four defining features: an urge to move the legs with unpleasant sensations, worse at rest, eased at least partly by moving, and worse in the evening or night. Leg symptoms that break that shape, especially ones movement does nothing for or ones that peak in the morning, are worth describing to your provider rather than filing under restless legs. Because low ferritin, folate, vitamin B12, and hemoglobin all track with RLS in pregnancy, ask whether those levels should be checked instead of assuming hormones explain everything. Symptoms still going well after delivery are also out of pattern, since 97 percent of pregnancy-onset cases cleared within a few days of birth. Trust your read on your own body. If something feels off beyond the list above, please consult your healthcare provider rather than waiting it out.