Restless Legs Syndrome With Iron Deficiency or Anaemia in the 3rd Trimester of Pregnancy

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)