Does Enoxaparin treatment have any effects on the placenta in women with unexplained histories of habitual abortion? A case control study

ABSTRACT BACKGROUND: It is very common to offer low molecular weight heparin (LMWH) medications to women with unexplained habitual abortion, to increase the livebirth rate. Although no benefit from LMWH has been clearly demonstrated, examination of the effects of enoxaparin on placental structure is lacking. OBJECTIVE: To assess placental structural changes in pregnancies treated with enoxaparin, compared with controls. DESIGN AND SETTING: Case-control study in an obstetrics and gynecology unit of a tertiary-level university hospital in Turkey. METHODS: Forty patients who had had term pregnancies and live births but also histories of habitual abortion were recruited for this study. Placentas were sampled using a systematic random sampling method. Tissue samples were obtained, embedded and sectioned for routine histological analyses. Hematoxylin and eosin staining was used. Surface area and length estimates from placental components were evaluated by using Image J. Cell proliferation and apoptosis were also assessed via immunohistochemistry. RESULTS: There were no significant differences between the groups regarding maternal age, abortion rate, birth weight or gestational age. Comparison of the enoxaparin and control groups showed that there were no significant differences in terms of surface area and ratios of placental components. We found that Bcl-2 was generally expressed at high levels in the enoxaparin group, while there was no difference in terms of Ki-67 between the groups. CONCLUSIONS: This study demonstrates that enoxaparin did not show any significant effect on the placental structure of cases that had histories of habitual abortion.

摘要

研究背景：目前临床常为原因不明复发性流产女性给予低分子肝素（low molecular weight heparin, LMWH）类药物，以提高活产率。尽管目前尚未明确证实低分子肝素的临床获益，但依诺肝素（enoxaparin）对胎盘结构影响的相关研究仍较为匮乏。

研究目的：本研究旨在对比依诺肝素治疗组与对照组孕妇的胎盘结构变化情况。

研究设计与研究地点：本研究为病例对照研究，开展于土耳其某三级大学医院的妇产科科室。

研究方法：本研究纳入40名既往有足月妊娠活产史且存在复发性流产病史的患者。采用系统随机抽样方法采集胎盘样本，获取组织标本后进行包埋、切片，行常规组织病理学分析，采用苏木精-伊红（hematoxylin and eosin）染色法。通过Image J软件评估胎盘各组成部分的表面积与长度参数。此外，借助免疫组织化学法检测细胞增殖与凋亡情况。

研究结果：两组患者的产妇年龄、流产次数、新生儿出生体重及孕周均无显著差异。对比依诺肝素组与对照组发现，胎盘各组成部分的表面积及占比均无显著差异。本研究观察到，依诺肝素组的Bcl-2蛋白普遍呈高表达，而两组的Ki-67表达水平无明显差异。

研究结论：本研究表明，依诺肝素对有复发性流产病史患者的胎盘结构无显著影响。