最近、不妊症や反復着床不全の患者に対してスクリーニング的に抗リン脂質抗体を測定する施設が散見されるが、その意義について検証した。凝固第XII因子、抗フォスファチジールエタノールアミン抗体 (aPE抗体)、抗カルジオリピンβ2GPI抗体とループスアンチコアグラントの測定を施行した。不妊症の中にも凝固第XII因子欠乏症とaPE抗体陽性例が不育症の1/2程度の頻度で存在した。不妊症や体外受精の反復着床不成功の原因として、抗リン脂質抗体やthrombophiliaを取り上げるか否かは、さまざまな意見があり、エビデンスをあきらかにできていない。抗リン脂質抗体やthrombophiliaがあるから、即ヘパリン使用とは推奨できない。但しこれらの患者は卵巣過剰刺激症候群 (OHSS) の兆候がある際は可能な限りの回避策をとり、OHSS症状が消失するまでは、抗凝固療法を続けるべきであろう。それ以外の場合は現時点で抗凝固療法を必要とするエビデンスはまだ不十分である。

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Advances in embryo freeze-thawing techniques can be cited as one factor in the development and widespread use of assisted reproductive medicine. It has been reported, however, that freezing causes hardening of the zona pellucida in embryos. Cryopreservation was initially carried out by slow freezing, but recently, vitrification has become a widely used, well-established method. In this study, we used vitrification to freeze-thaw mouse blastcysts obtained by in vitro fertilization, and compared fresh blastcysts with blastcysts directly after freeze-thawing and after 2, 4, 6, 12, and 24 h of recovery culture using scanning electron microscopy (SEM). The reticulate structure seen in fresh blastcysts was observed to be in a closed state after freeze-thawing, suggesting hardening of the zona pellucida. During recovery culture, the structure of the zona pellucida gradually approached that of fresh blastcysts, but was not fully restored even after extending the recovery culture period. These findings suggest that freezing affects the structure of the zona pellucida, which could not be fully restored despite some degree of recovery after recovery culture.

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