*Case Report* **Extremely Rare Case of Fetal Anemia Due to Mitochondrial Disease Managed with Intrauterine Transfusion**

**Jinha Chung, Mi-Young Lee, Jin-Hoon Chung and Hye-Sung Won \***

Department of Obstetrics and Gynecology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea; waterlilyv@naver.com (J.C.); poptwinkle@hanmail.net (M.-Y.L.); sabi0515@hanmail.net (J.-H.C.)

**\*** Correspondence: hswon@amc.seoul.kr

**Abstract:** This report describes a rare case of fetal anemia, confirmed as a mitochondrial disease after birth, treated with intrauterine transfusion (IUT). Although mitochondrial diseases have been described in newborns, research on their prenatal features is lacking. A patient was referred to our institution at 32 gestational weeks owing to fetal hydrops. Fetal anemia was confirmed by cordocentesis. After IUT had been performed three times, the anemia and associated fetal hydrops showed improvement. However, after birth, the neonate had recurrent pancytopenia and lactic acidosis. He was eventually diagnosed with Pearson syndrome and died 2 months after birth. This is the first case report of fetal anemia associated with mitochondrial disease managed with IUT.

**Keywords:** anemia; blood transfusion; case report; hydrops fetalis; mitochondrial diseases; Pearson syndrome
