Pathological skin scars, caused by cesarean section, affected younger mothers esthetically and psychosocially and to some extent frustrated obstetricians and dermatologists. Umbilical cord mesenchymal stem cells (UC-MSCs), as a population of multipotent cells, are abundant in human tissues, providing several possibilities for their effects on skin scar tissues. Herein, we performed a randomized, double-blind, placebo-controlled, three-arm clinical trial, aiming to assess the efficacy and safety of UC-MSCs in the treatment of cesarean section skin scars among primiparous singleton pregnant women. Ninety primiparous singleton pregnant women undergoing elective cesarean section were randomly allocated to receive placebo, low-dose (3 × 106 cells), or high-dose (6 × 106 cells) transdermal hydrogel UC-MSCs on the surface of the skin incision. The primary outcome was cesarean section skin scars followed after the sixth month, assessed by the Vancouver Scar Scale (VSS). All the participants completed their trial of the primary outcome according to the protocol. The mean score of estimated total VSS was 5.52 in all participants at the sixth-month follow-up, with 6.43 in the placebo group, 5.18 in the low-dose group, and 4.71 in the high-dose group, respectively. No significant difference was found between-group in the mean scores for VSS at the sixth month. Additional prespecified secondary outcomes were not found with significant differences among groups either. No obvious side effects or adverse effects were reported in any of the three arms. This randomized clinical trial showed that UC-MSCs did not demonstrate the effects of improvement of cesarean section skin scars. ClinicalTrials.gov identifier, NCT02772289. Registered on 13 May 2016.

中文翻译：

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脐带间充质干细胞治疗剖宫产皮肤瘢痕的疗效和安全性：一项随机临床试验。

由剖宫产引起的病理性皮肤疤痕从美学和心理上影响了年轻的母亲，并在一定程度上使产科医生和皮肤科医生感到沮丧。脐带间充质干细胞（UC-MSC），作为一种多能细胞，在人体组织中很丰富，为它们对皮肤疤痕组织的作用提供了几种可能性。本文中，我们进行了一项随机，双盲，安慰剂对照的三臂临床试验，旨在评估UC-MSC在初生单胎孕妇剖宫产皮肤疤痕中的疗效和安全性。随机选择接受剖宫产术的初产单胎孕妇90例，在皮肤切口表面接受安慰剂，低剂量（3×106细胞）或高剂量（6×106细胞）透皮水凝胶UC-MSC。主要结果是剖腹产皮肤疤痕，随后在第六个月后通过温哥华疤痕量表（VSS）进行评估。所有参与者均按照方案完成了对主要结局的试验。在第六个月的随访中，所有参与者的估计总VSS平均得分为5.52，安慰剂组为6.43，低剂量组为5.18，高剂量组为4.71。第六个月，VSS的平均得分在组间没有发现显着差异。两组之间也没有发现其他预先指定的次要结局，且差异显着。三组中的任何一组均未报告明显的副作用或不良反应。这项随机临床试验表明，UC-MSCs没有显示出改善剖宫产皮肤疤痕的效果。临床试验。gov标识符，NCT02772289。2016年5月13日注册。