Not Just a Fidget: Why Restless Leg Syndrome During Pregnancy Is a Clinical Signal, Not a Trifle

Women often attribute the "tingles" and irresistible urge to move their legs in the evenings to the usual burdens of pregnancy. An editorial in the journal SLEEP urges against this: restless legs syndrome (RLS) in pregnancy is a common and clinically significant condition closely associated with iron deficiency in the brain, sleep disorders and, probably, adverse obstetric outcomes. The authors insist: recognizing RLS means not missing the chance to check and correct iron in time, improve sleep and well-being of the expectant mother.

Background of the study

RLS is a neurological disorder characterized by an evening increase in discomfort in the legs and an irresistible urge to move them; symptoms interfere with falling and maintaining sleep. RLS is much more common in pregnant women than in the general population: meta-analyses estimate the prevalence at about 21% for the entire pregnancy and about 23% in the third trimester, although estimates vary by region and method.

The key to the pathophysiology is brain iron deficiency. Even with normal peripheral parameters, patients with RLS show signs of relative iron deficiency in the central nervous system; symptoms are usually exacerbated by systemic iron deficiency. Pregnancy is a period of increased iron demand, making RLS particularly likely and "biologically plausible."

Why is this important now? Firstly, RLS is often underestimated: the symptom can easily be confused with “normal” leg fatigue, and screening for RLS in obstetric practice is not implemented everywhere. Secondly, there is a growing body of data on the relationship between gestational RLS and hypertensive disorders of pregnancy and postpartum depression (although the results are not uniform in terms of cesarean section, premature birth and birth weight).

The editorial in SLEEP makes a simple point: If RLS is not recognized as a possible symptom of iron deficiency, the window for timely evaluation and correction is lost - and therefore for improving the pregnant woman's sleep, mood, and daytime functioning.

Finally, with the growing attention to women's health comes a growing demand for practical, low-risk interventions. In the case of RLS, this primarily includes optimizing iron status according to obstetric standards, behavioral sleep measures, and careful selection of pharmacotherapy in severe forms.

Why is this important?

RLS is not a “harmless little thing”, but a modifiable cause of sleep and quality of life disruption during one of the most vulnerable periods.

• For female patients: persistent “pins and needles”/pulling sensations in the legs, which intensify in the evening and interfere with sleep, are a reason to tell your doctor; this may indicate iron deficiency and can be corrected.
• For clinicians (ACU/OAG/neurologists/somnologists): identifying RLS provides a trigger for iron testing and targeted interventions potentially impacting both sleep and obstetric risks.

Purpose of the study

The SLEEP editorial aims to focus obstetricians, neurologists and sleep specialists on the significance of RLS in pregnancy: to explain the neurobiological basis (iron deficiency in the brain), to summarize the epidemiology and associated risks, to remind about simple diagnostic steps and evidence-based interventions that can be integrated into routine practice now.

Materials and methods

This is an editorial commentary/short literature review, not an original clinical study: the authors draw on contemporary meta-analyses of prevalence, data on the association of RLS with gestational outcomes, and experimental clinical work on the role of iron in the pathogenesis of RLS, with an emphasis on pregnancy.

Results and interpretation

Key messages from the editorial board: (1) RLS in pregnancy is common but often unrecognized; (2) iron deficiency (including central) is a central mechanism, so RLS should be considered a “clinical marker” for iron assessment; (3) sleep disturbances in RLS impair daytime functioning and may increase stress/depressive symptoms; (4) gestational RLS is associated with hypertensive disorders and preeclampsia (observational level of evidence); (5) targeted iron correction and behavioral sleep interventions are the preferred first line in pregnancy. The final interpretation is simple: add questions about RLS to the standard obstetric questionnaire and follow the algorithm “detected → check iron → correct”.

Discussion

The article fits into the modern picture: "sleep is part of maternal health." Unlike many conditions of half-deciphered etiology, RLS has a clear biological substrate (iron) and simple clinical diagnostics - targeted questions about evening increase in discomfort, relief with movement and nighttime disturbances are enough. At the same time, the authors honestly indicate the limits of knowledge: some associations with obstetric outcomes are based on observational data, confounding and reverse causality are possible; prospective cohort studies and interventional RCTs with objective sleep metrics are needed. But there is no need to wait for an ideal RCT to ask a pregnant woman about RLS symptoms and assess ferritin.

Practical significance

What can be done already in the routine - without reinventing routes:

• Include 1-2 screening questions about typical RLS symptoms in the pregnancy questionnaire; if suspected, assess iron status according to obstetric standards and first exhaust non-pharmacological and nutritional measures (sleep hygiene, physical activity during the day, iron/folate correction in case of deficiency; drug therapy - only according to strict indications and in a specialized consultation).
• Inform patient: RLS is common and treatment-directed; report “red flags” (worsening symptoms, severe sleep/mood disturbance) when to return to doctor sooner; schedule postpartum symptom monitoring (usually regresses).

Restrictions

The content is an editorial opinion, not a systematic review with meta-analysis; no new causal relationships are established. The evidence base for obstetric outcomes is heterogeneous, with most studies being observational and relying on self-reporting of RLS symptoms. Any decisions on drug therapy in pregnancy should be consistent with national guidelines and taken on an individual basis.

Conclusions

RLS in pregnancy is a common, clinically significant and modifiable factor of poor sleep and well-being. Its recognition opens a "window of opportunity": to check and adjust iron, improve sleep, reduce symptom load and, possibly, indirectly influence pregnancy risks. For this, a small step is enough - to add questions about RLS to the routine obstetric survey and build a simple algorithm of actions.

Source: Setteducato M., Bliwise DL, Trotti LM Don't Shake It Off: The Importance of Restless Legs Syndrome in Pregnancy. SLEEP. 2025 Sep 1:zsaf266. DOI: 10.1093/sleep/zsaf266.