In pregnancy Restless Legs Syndrome(RLS) is more common than in the general population. During pregnancy iron tablets are the only available safe medication but their efficacy is rather poor. It is the aim of this study to examine the efficacy, practicability and safety of the drug Ferinject® containing the active agent Ferric carboxymaltose for the therapy of Restless Legs Syndrome(RLS) during pregnancy in the case of iron deficiency or anaemia.

20 women with RLS and iron deficiency and/ or anaemia in the third trimester of pregnancy will receive intravenous Ferric carboxymaltose in one or two single doses. Repeated blood tests, pre-and post-therapy actigraphy as well as repeated answering of questionnaires concerning Restless Legs Syndrome(RLS)-symptoms and sleep quality will show the effect of iv-Iron supplementation on Restless Legs Syndrome(RLS)-symptoms during pregnancy.

• Trial with medicinal product

Inclusion criteria:

1. Pregnant women, singleton pregnancy, in the 3rd trimester

2. Iron Deficiency (Anaemia) defined as Serum Ferritin < 35ug/l with or without Hb < 11g/dl.

3. Fulfilling the 4 criteria of the International Restless Legs Study Group (IRLSS)

   • Uncomfortable and unpleasant sensations in the legs
   • An urge to move the legs due to this discomfort and worsening of the symptoms when resting
   • The unpleasant sensations are being relieved by movement such as walking or stretching
   • Worsening of the symptoms in the evening or night

4. RLS score > 20 (defined as modest to severe RLS symptoms) or RLS symptoms = 3 times per week

5. Patients = 18 years

6. Signed informed consent provided

Exclusion criteria: Criteria

1. Age < 18 years
2. Multiple pregnancy
3. Depression, psychiatric disease
4. Severe internal underlying disease, that causes fatigue and sleepiness and thus may confound the outcome measures
5. Abuse of alcohol, coffee or drugs
6. Medication (antipsychotics, antihistaminics, tricyclic or SSRI/SNRI antidepressants, L-Dopa, antidopaminergic medication, medium to strong opioids, antiepileptic medication).
7. RLS not due to iron deficiency: RLS secondary to other central nervous system disease or injury. Such disorders included peripheral neuropathy, neurodegenerative disorders and multiple sclerosis
8. RLS secondary to chronic kidney disease
9. Relevant chronic pain syndrome of the extremities other than RLS
10. Known proneness to allergic reactions
11. Known hypersensitivity to Ferric carboxymaltose
12. Relevant disorders of iron metabolism of other aetiology than iron deficiency (e.g. hemochromatosis, hemosiderosis)