Search for effective artificial amniotic fluid purification method

• Project/Area Number: 17K16295
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Embryonic/Neonatal medicine
• Research Institution: Tohoku University
• Principal Investigator: Sato Shinichi 東北大学, 大学病院, 助手 (30770359)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 人工子宮 / ヒツジ / 子宮内感染 / 人工羊水 / 早産児 / 人工胎盤 / 羊水炎

Outline of Final Research Achievements

We developed an artificial placenta system for improving the prognosis of very low birth weight infants in animal experiments using sheep fetuses. In the study, it was pointed out that immature and weakly resistant fetuses are prone to fall into bacteremia and sepsis due to microorganisms grown in artificial amniotic fluid. Therefore, the purpose of this study was to establish an amniotic fluid purification system.
A 0.2 μm filter and ultraviolet irradiation were introduced into the artificial amniotic fluid circulation, but it was not easy to prevent bacterial growth in amniotic fluid, and immature sheep fetuses developed sepsis. However, subsequent experiments showed that the replacement of artificial amniotic fluid every 6 hours could prevent the development of sepsis in immature fetuses (103 days gestation, average body weight 1.20 kg).

Academic Significance and Societal Importance of the Research Achievements

超低出生体重児の予後の改善を目的とした人工胎盤システムにおいて，人工羊水の浄化は必要不可欠である．そこで未熟な胎児においても人工羊水を入れ替えることで敗血症を予防できることが示された意義は大きい．
現在胎児の成長や発達に羊水成分の与える影響は全く解明されていない．そのため本システムを採用するのであれば，今後は人工羊水を入れ替えることで生じる成長障害に着目した解析が必要である．一方で本来の子宮内における羊水の主成分は胎児尿であり，人工子宮内においてより生理的な環境を胎児に提供するのであれば，無菌を維持できる閉鎖式人工子宮バッグやより効果的な羊水循環濾過システムの開発が望まれる．

Research Products

• [Int'l Joint Research] The University of Western Australia(オーストラリア)
• [Int'l Joint Research] The University of Western Australia(オーストラリア)
• [Int'l Joint Research] The University of Western Australia(Australia)
• [Journal Article] Successful use of an artificial placenta to support extremely preterm ovine fetuses at the border of viability (2019)
  • Author(s): Usuda Haruo、Watanabe Shimpei、Saito Masatoshi、Sato Shinichi、Musk Gabrielle C.、Fee Erin、Carter Sean、Kumagai Yusaku、Takahashi Tsukasa、Kawamura Shinichi、Hanita Takushi、Kure Shigeo、Yaegashi Nobuo、Newnham John P.、Kemp Matthew W.
  • Journal Title: American Journal of Obstetrics and Gynecology Volume: ー Issue: 1 Pages: 69.e1-69.e17
  • DOI: 10.1016/j.ajog.2019.03.001
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Successful maintenance of key physiological parameters in preterm lambs treated with ex?vivo uterine environment therapy for a period of 1 week (2017)
  • Author(s): Usuda Haruo、Watanabe Shimpei、Miura Yuichiro、Saito Masatoshi、Musk Gabrielle C.、Rittenschober-B?hm Judith、Ikeda Hideyuki、Sato Shinichi、Hanita Takushi、Matsuda Tadashi、Jobe Alan H.、Newnham John P.、Stock Sarah J.、Kemp Matthew W.
  • Journal Title: Am J Obstet Gynecol. Volume: 217 Issue: 4 Pages: 457.e1-457.e13
  • DOI: 10.1016/j.ajog.2017.05.046
  • Peer Reviewed / Int'l Joint Research