This case report concerns a pregnant multipara (age: 27 years) in the 16th gestational week. She developed a sudden onset of paraesthesia in her left lower arm although injecting dalteparin 5000 IU once daily subcutaneously (s. c.) due to a heterozygous factor V Leiden mutation and a prior miscarriage in the first pregnancy and preeclampsia in her third pregnancy. After the miscarriage she delivered two healthy children under prophylactic anticoagulation with low molecular weight heparin (LMWH). Now via magnetic resonance imaging (MRI) she was diagnosed as having multiple cerebral ischaemic lesions. Further workup revealed the presence of a patent foramen ovale (PFO) II° but no venous thrombosis in her legs. She was then treated with dalteparin 5000 IU twice daily by subcutaneous injections. At 19th gestational week she developed paraesthesia in her left lower arm again. The MRI showed a cortical lesion in the territory of the right median cerebral artery. The anticoagulation dose was increased stepwise under surveillance of the anti-FXa-level 3-4 h after subcutaneous injections aiming to achieve the supratherapeutic range of 1.2-1.5 IU/ml anti-Xa-units. No more neurological symptoms appeared under this antithrombotic therapy. The patient delivered by induction of labor at the 38th gestational week.
Keywords: PFO; Schwangerschaft; Thrombophilie.