一項新的非選擇性臨床試驗表明，許多因染色體異常而被丟棄的體外受精胚胎可能會導(dǎo)致成功懷孕和健康嬰兒。

　　目前，只有不到3%的鑲嵌胚胎（混合了正常細胞和非整倍體細胞）在試管嬰兒期間被轉(zhuǎn)移到子宮中，因為他們認為它們不可行。這種做法限制了IVF，因為患者可以使用的替*胚胎很少，盡管有有限的證據(jù)表明鑲嵌胚胎是不可行的，因為少數(shù)異常細胞可能不會影響胎兒發(fā)育。

　　'眾所周知，假定的鑲嵌胚胎可以發(fā)育成足月并生出健康的嬰兒，但之前許多研究這個問題的研究都受到了對預(yù)后不良患者人群的選擇偏倚的影響，因為他們以前曾植入失敗該研究的第一作者、意大利馬羅斯蒂卡Igenomix實驗室主任安東尼奧·卡帕爾博博士說，該實驗室專門從事基因組檢測服務(wù)。

　　在發(fā)表在《美國人類遺傳學(xué)雜志》上的臨床試驗中，胚胎進行了植入前基因檢測，專門尋找鑲嵌非整倍體。除了整倍體胚胎（沒有非整倍體的胚胎）之外，具有低級嵌合（20%到30%的非整倍體細胞）和中等嵌合（30%到50%的非整倍體細胞）的胚胎被盲目地報告為整倍體并被植入。這種策略避免了偏見，因為任何符合定義標準的胚胎都可以用于植入。

　　研究人員發(fā)現(xiàn)，在484個整倍體、282個低級嵌合體和131個中級嵌合體胚胎中，嵌合體胚胎植入子宮的可能性與正常胚胎一樣，并且成為健康嬰兒的可能性相同。學(xué)期。三組的產(chǎn)科和新生兒結(jié)局也相似。

　　三組之間的流產(chǎn)率相似，并且在所調(diào)查的導(dǎo)致流產(chǎn)的妊娠中，沒有一個是由于非整倍體引起的。

　　'這是一個在過去十年中引起了很多爭議的領(lǐng)域，有些人盲目相信，有些人認為這是錯誤的。它已經(jīng)分裂了這個領(lǐng)域，沒有參與這項研究的國王生育中心主任Ippokratis Sarris博士在《電訊報》上評論道。'臨床醫(yī)生和醫(yī)生都在問：“我應(yīng)該如何處理馬賽克胚胎？”我們越來越有信心放回馬賽克胚胎并看看會發(fā)生什么。

　　研究人員希望這項研究能夠改變目前關(guān)于在IVF治療之前使用和報告鑲嵌胚胎的指南，從而使患者能夠?qū)﹁偳杜咛サ囊浦沧龀龈髦堑臎Q定，根據(jù)試驗，鑲嵌胚胎可以被認為是健康和正常的。

　　Many IVF embryos discarded due to chromosomal abnormalities could lead to viable pregnancies and healthy babies,a new non-selection clinical trial has suggested.

　　Currently fewer than three percent of mosaic embryos,which have a mixture of normal and aneuploid cells,are transferred into the uterus during IVF due to a belief they are not viable.This practice limits IVF where few alternative embryos are available to a patient,although there is limited evidence to suggest that mosaic embryos are not viable as a few abnormal cells might not affect fetal development.

　　'It was already known that putative mosaic embryos can develop to term and make healthy babies,but many of the previous studies that looked at this issue were affected by selection bias toward a population of patients that had a poor prognosis because they had previously failed implantations with euploid embryos,'said first author of the study Dr Antonio Capalbo,laboratory director at Igenomix,Marostica,Italy,which specialises in genomic testing services.

　　In the clinical trial,published in the journal American Journal of Human Genetics,embryos were tested with pre-implantation genetic testing that looked specifically for mosaic aneuploidy.In addition to euploid embryos(those with no aneuploidy),embryos with low-grade mosaicism(20 to 30 percent aneuploid cells)and medium-grade mosaicism(30 to 50 percent aneuploid cells)were blindly reported as euploid and implanted.This strategy avoided bias as any embryo that fitted the defined criteria could be used for implantation.

　　The investigators found that across 484 euploid,282 low-grade mosaic,and 131 medium-grade mosaic embryos,the mosaic embryos were as likely to implant in the uterus as the normal embryos,and had the same likelihood of becoming a healthy baby carried to term.The obstetric and neonatal outcomes were also similar across the three groups.

　　Miscarriage rates were similar across the three groups and of the pregnancies which resulted in miscarriage which were investigated,none were due to aneuploidy.

　　'This is an area that has created a lot of controversy over the last decade,with some who believe it blindly and some who believe it's wrong.It has divided the field'Dr Ippokratis Sarris,director of King's Fertility,who was not involved in the study,commented in the Telegraph.'Clinicians and doctors are asking:"what should I do with mosaic embryos?"We're becoming more confident in putting back mosaic embryos and seeing what happens.'

　　The researchers expect the study to change current guidelines on the use and reporting of mosaic embryos prior to IVF treatment,thus allowing patients to make more informed decisions about the transfer of mosaic embryos,which can be deemed healthy and normal according to the trial.