Therapeutic amnioinfusion for chronic abruption-oligohydramnios sequence: A possible prevention of the infant respiratory disease Ayako Morita 1 , Eiji Kondoh 1 , Kaoru Kawasaki 1 , Kohei Fujita 1 , Haruta Mogami 1 , Sachiko Minamiguchi 2 and Ikuo Konishi 1 Departments of 1 Gynecology and Obstetrics, and 2 Diagnostic Pathology, Kyoto University, Kyoto, Japan Abstract Chronic abruption-oligohydramnios sequence (CAOS), characterized by chronic vaginal bleeding and oligo- hydramnios, is associated with adverse pregnancy outcomes, including preterm delivery and lung problems in the infant. Fetal lung damage may be induced by not only oligohydramnios but also iron-induced oxidative stress through chronic aspiration of bloody substances in amniotic fluid. We describe a pregnancy complicated with CAOS that was managed with repeated amnioinfusions. This is the first report showing that amnioinfusions succeeded in a significant reduction in high concentrations of iron, lactose dehydrogenase, and 8-hydroxy-2′-deoxyguanosine, a marker of oxidative DNA damage, in the amniotic fluid complicated by CAOS. The baby, born at 26 weeks’ gestation via cesarean, was discharged home without supplemental oxygen 116 days after birth. Key words: amnioinfusion, chronic abruption-oligohydramnios sequence, diffuse chorioamniotic hemosid- erosis, lung injury, oxidative stress. Introduction Chronic abruption-oligohydramnios sequence (CAOS) was first defined by Elliott et al. by the following crite- ria: (i) clinically significant vaginal bleeding in the absence of placenta previa or other identifiable source of bleeding; (ii) amniotic fluid volume initially docu- mented as normal; and (iii) oligohydramnios (amniotic fluid index ≤5 cm) eventually developing without con- current evidence of ruptured membranes. 1 CAOS is typified clinically by recurrent episodes of substantial vaginal bleeding in the early second trimester of pregnancy. CAOS is attributed to chronic peripheral separation of the placenta, including subchorionic hematoma, which results in the release of hemoglobin and its degradation products into the amniotic cavity. These products are phagocytosed by chorionic mac- rophages to form diffuse deposition of hemosiderin in chorionic plate or membranes. CAOS is therefore closely associated pathologically with diffuse cho- rioamniotic hemosiderosis (DCH). 2 A pregnancy complicated with CAOS is well known to have adverse perinatal outcomes. 1,3,4 CAOS often results in preterm delivery at approximately 28 weeks of gestation. 1 Moreover, CAOS can cause a high neona- tal mortality rate due to respiratory problems or per- sistent pulmonary hypertension. 1,3,4 Fetal and neonatal lung damage may be attributed to chronic aspiration of bloody substances in amniotic fluid, which can lead to persistent iron-induced oxidative stress to the imma- ture fetal lung. To date, optimal management for a pregnancy complicated with CAOS has yet to Received: April 25 2013. Accepted: September 3 2013. Reprint request to: Eiji Kondoh, Department of Gynecology and Obstetrics, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan. Email: kondo@kuhp.kyoto-u.ac.jp doi:10.1111/jog.12289 J. Obstet. Gynaecol. Res. 2014 © 2014 The Authors 1 Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology