Evaluation of 1100 couples with recurrent pregnancy loss using conventional cytogenetic, PGD, and PGS: hype or hope

Abstract

Recurrent pregnancy loss (RPL) is an important clinical problem, mostly resulting from chromosomal or genetic defects, while in 30–60% of cases, it is idiopathic. The aim of this study is to evaluate the frequency and types of chromosomal abnormalities, also pre-implantation genetic diagnosis (PGD) and pre-implantation genetic screening (PGS) outcomes among Iranian couples with RPL. This retrospective study was conducted on 1100 Iranian couples (2200 individuals) with RPL referred to Royan Institute between 2008 and 2014. Karyotyping had been performed using standard cytogenetic techniques. PGD results of RPL patients with abnormal karyotypes and PGS results of RPL patients with normal karyotypes were also analyzed. The frequency of chromosomal abnormalities in these patients was 4.95%. Women demonstrated more abnormalities (6.82%) in comparison to men (3.09%). The successful rate of pregnancy after PGD and PGS was 52 and 18.64%, respectively. The observation of 4.95% chromosomal abnormalities among the patients with RPL could support this hypothesis that there is a direct relationship between chromosomal abnormalities and RPL. More than half of the patients who underwent PGD had successful pregnancy; therefore, this approach can improve the success rate of pregnancy in them. The results of PGS cycles showed that this technique could increase the live birth rate in RPL patients.

Chinese abstract

反复性流产(RPL)是一个重要的临床疾病，主要由染色体或基因缺陷造成，30 - 60%的情况下特发。本研究的目的是评估染色体异常的频率和类型，并对伊朗患有复发性流产夫妇进行胚胎植入前基因诊断(PGD)和胚胎植入前基因筛查(PGS)。本回顾性研究由Royan研究所收集了2008至2014年1100对患有PRL的伊朗夫妇(2200名个体)的实验数据。该研究使用标准细胞遗传学技术进行核型分析。对异常核型的RPL患者的胚胎植入前基因诊断(PGD)以及正常核型的PRL患者的胚胎植入前基因筛查(PGS)均进行分析。这些患者的染色体异常率为4.95%。与女性异常(6.82%)相比，男性异常(3.09%)较少。PGD以及PGS后的妊娠成功率分别为52%和18.64%。RPL患者的4.95%的染色体异常率支持了假说：染色体异常与RPL之间有直接关系。超过一半的接受PGD的患者已经成功妊娠，因此，这种方法可以提高成功妊娠率。PGS的测量结果表明，这种技术可能会增加RPL病人的活产率。

• Chromosomal abnormalities
• cytogenetic
• pre-implantation genetic diagnosis
• pre-implantation genetic screening
• recurrent pregnancy loss

Acknowledgements

The authors would like to express their attitude to staff of cytogenetic and PGD labs of Royan Institute for their technical assistance.

Declaration of interest

The authors confirm no co-operation with the Iranian government and report no declarations of interest.

This research was financially supported by a grant from the Royan Institute as a non-governmental and non-profit center.