Ultraschall Med 2016; 37 - PS5_09
DOI: 10.1055/s-0036-1587872

Maternal Acetylcholine-Receptor Autoantibodies causing recurrent fetal Arthrogryposis

S Verlohren 1, CE Ott 2, A Meisel 3, C Dame 4, W Henrich 1
  • 1Charité – Universitätsmedizin Berlin, Department of Obstetrics, Berlin, Germany
  • 2Charité – Universitätsmedizin Berlin, Medical Genetics and Human Genetics, Berlin, Germany
  • 3Charité – Universitätsmedizin Berlin, Neurology, Berlin, Germany
  • 4Charité – Universitätsmedizin Berlin, Neonatology, Berlin, Germany

Background: The foetal Arthrogryposis multiplex congenita is defined as the occurrence of malposition of two joints in at least two body regions. This descriptive definition comprises a multitude of genetic and non-genetic causes. The detection of the underlying aetiology is reported to be approximately 5%. A rare non-genetic cause of foetal Arthrogryposis is a maternal myasthenia gravis or maternal autoantibodies against the Acetylcholine-Receptor (AChR-AA). By passing the placenta, they cause foetal akinesia deformation sequence.

Case report: A healthy 28-year-old primigravida presents in 13 weeks of gestation for first trimester screening. A cystic hygroma is detected and chorionic villous sampling is performed yielding a normal fetal karyotype. In the 16 weeks scan, a fixed extension in the knee joints, a fixed flexion in the elbow joint is detected. In 21 weeks the patient is referred with hydrops fetalis and massive skin oedema. The liver function tests were abnormal and pregnancy was terminated due to impending mirror syndrome. Six months later the patient presents with a new pregnancy. The first trimester- as well as 16 weeks scan were uneventful. In the 22 weeks scan, the fetus exhibited extended legs, talipes on both sides, fixed flexion in the elbow joints, retrognathia and polyhydramnios. The karyotype was normal. A genetic counselling was performed and maternal AChR-AA were determined, which were elevated 40x above normal. Due to progressive fetal akinesia including thorax deformation, pregnancy was terminated.

Conclusion: Maternal AChR-AA constitute a rare cause of fetal Arthrogryposis, also in the absence of symptoms of myasthenia gravis in the pregnant mother. By passing the placenta, they cause foetal akinesia deformation sequence. Differential diagnostic workup, especially in recurrent cases, should include their evaluation. Knowledge about their presence allows for diagnostic intervention such as plasmapheresis before the subsequent pregnancy.