日本新生児成育医学会雑誌　36(2)：140-146；2024　

日本新生児成育医学会雑誌　第36巻　第2号　140 ～ 146頁（2024年）

受付日：2023．12．07

受理日：2024．04．26

非典型的な経過を辿った慢性母児間輸血症候群の重症例

A Case of Severe Chronic Fetomaternal Hemorrhage with an Atypical Course

＊ 1 済生会山形済生病院　小児科，＊ 2 同　産婦人科

＊ 1 Department of Pediatrics, Saiseikai Yamagata Saisei Hospital， ＊ 2 Department of Obstetrics and Gynecology, Saiseikai Yamagata Saisei Hospital

松内祥子＊ 1・山口　翔＊ 1・青木倉揚＊ 1・大貫　毅＊ 2・阪西通夫＊ 2・赤羽和博＊ 1

Shoko MATSU-UCHI ＊ 1，Sho YAMAGUCHI ＊ 1，Kuraaki AOKI ＊ 1，Tsuyoshi ONUKI ＊ 2，Michio BANZAI ＊ 2，Kazuhiro AKABA ＊ 1

Key Words：fetomaternal transfusion，fetal hemoglobin，alpha-fetoprotein，neonatal anemia，fetal movements

母児間輸血症候群（fetomaternal hemorrhage：FMH）では，胎児が短時間で急速に失血する急性型と比べ，長 時間かけて緩徐に失血する慢性型は代償機転が働くため軽症が多いとされている。我々は急性期管理に難渋し，神 経学的後遺症を認めた慢性FMH の非典型例を経験した。母は妊娠37 週1 日に前日からの胎動消失を訴え受診した。 胎児徐脈と胎児の胸腹水を認め，同日緊急帝王切開術を行った。出生した女児は体重 2,556g，Apgar スコア1/1/1 （1/5/10 分），Hb 1.9g/dL，Ht 7％，網赤血球 18.1％，全身蒼白で浮腫があり，Sarnat 分類重症の低酸素性虚血性 脳症を認めた。母体HbF は0.5％と高値ではないが，母体AFP は2,960ng/mL と高値だった。慢性経過のFMH と 考えられたが，強い呼吸循環不全を呈し，頭部MRI 検査で多嚢胞性脳軟化症と診断された。現在1 歳で脳性麻痺 と発達遅滞を認めている。慢性FMH は胎児失血量のわりに予後良好だとする報告が多いが，その重症度には幅が ある。

Fetomaternal hemorrhage （FMH） is defined as a transfusion of fetal blood into maternal blood circulation, which can cause severe neonatal anemia. In acute FMH, blood loss is rapid, and aggressive resuscitation at birth is necessary；subsequent development of significant hypotension and acidosis is common. Conversely, in chronic FMH, even for extensive blood loss, the progression of anemia is slow and does not cause circulatory failure, owing to compensatory mechanisms. This report describes a case of severe FMH with respiratory and circulatory failure and neurologic sequelae, despite a chronic course. A 38-year-old pregnant woman had complained about a reduction in fetal movements；subsequently, at 37 weeks and 1 day of gestation, a category-1 cesarean section was performed because of fetal bradycardia, fetal pleural effusions, and ascites. A female infant was delivered, weighing 2,556 g and having an Apgar score of 1 at 1, 5, and 10 min after birth. The umbilical cord arterial pH was 6.92. She was extremely pale, had edema, and had severe hypoxic-ischemic encephalopathy classified based on Sarnat staging. Severe anemia in the infant was indicated by a hemoglobin level of 1.9 g/dL, hematocrit of 7％, and a reticulocyte count of 18.1％. Respiratory and circulatory failures were severe, requiring intensive care and blood transfusion. The maternal fetal hemoglobin level was 0.5％, as measured using high-performance liquid chromatography；hence, initially, FMH was deemed unlikely. However, the maternal alpha-fetoprotein level was high （2,960 ng/mL）, indicating the presence of FMH. Magnetic resonance imaging of the brain on postnatal day 19 revealed polycystic encephalomalacia. The infant is currently 1 year old and has cerebral palsy and psychomotor developmental delay. This case was classified as chronic FMH with a severe course, and the prognosis was not favorable. It is important to consider that the severity and prognosis may vary in chronic FMH.