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Assisted hatching on assisted conception (IVF and ICSI)

  • Review
  • Intervention

Authors


Abstract

Background

Failure of implantation and conception may result from an inability of the blastocyst to escape from its outer coat, known as the zona pellucida. Artificial disruption of this coat is known as assisted hatching (AH) and has been proposed as a method for improving the success of assisted conception.

Objectives

To determine whether assisted hatching (AH) of embryos facilitates live births and clinical pregnancy.

Search methods

We previously searched the Cochrane Menstrual Disorders and Subfertility Group Specialsed Register (February 2007), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2007), MEDLINE (1966 to February 2007) and EMBASE (1980 to February 2007).

Selection criteria

Two authors identified and independently screened trials. We included randomised controlled trials (RCTs) of AH (mechanical, chemical or laser disruption of the zona pellucida prior to embryo replacement) versus no AH, which reported live birth or clinical pregnancy rates.

Data collection and analysis

Two authors independently performed qualitative assessments and data extraction.

Main results

Twenty-eight trials reported clinical pregnancy data, including 1228 clinical pregnancies in 3646 women. There was no significant difference in the odds of live births in the AH compared with control groups (seven RCTs; OR 1.13, 95% CI 0.83 to 1.55; 255 births from 719 women, with no heterogeneity (P = 0.37) or inconsistency I2 = 8%)). We also analysed the clinical pregnancy rate from the seven studies that reported live births, which was non-significant (OR 1.13, 95% CI 0.83 to 1.54). Inclusion of studies which were more robust in methodology showed an increase in clinical pregnancy rate which was just statistically significant (16 RCTs; OR 1.20, 95% CI 1.00 to 1.45, P = 0.05). Analysis of all the studies included in this update (28 RCTs) showed a marked increase in clinical pregnancy rate (OR 1.29, 95% CI 1.12 to 1.49).

Miscarriage rates per women were similar in both groups (14 RCTs; OR 1.13, 95% CI 0.74 to 1.73). Multiple pregnancy rates per woman were significantly increased in women who were randomised to AH compared with women in control groups (12 RCTs; OR 1.67, 95% CI 1.24 to 2.26).

Authors' conclusions

The improvement in clinical pregnancy rate (CPR) with AH means that a clinic with a success rate of 25% could anticipate improving the CPR to between 29% and 49%, all things being equal. The included trials provided insufficient data to investigate the impact of assisted hatching on several important outcomes.

摘要

背景

對於人工受孕所使用的輔助胚胎孵化(體外受精 & 卵細胞質內單精蟲顯微注射)

著床與受精的失敗,可能的原因是囊胚無法從它外面的包覆層中脫離出來,而那個包覆層也就是我們所知道的卵透明帶(zona pellucida)。細胞體外的培養條件與/或是產婦的年齡逐漸增加,都可能會改變卵透明帶的本體結構,並且造成孵化方面的困難。就人們所知,以人工的方法來破壞這個包覆層,也就是輔助胚胎孵化(AH),已經被認為是一種可以提高人工受孕之成功率的方法。

目標

要確認對胚胎所進行的輔助胚胎孵化(AH)是否可以提高產下活胎的機率,並促進臨床懷孕率,還有它是否會帶來負面的結果(例如懷上多胞胎與流產)。

搜尋策略

我們搜尋 Cochrane Menstrual Disorders以及Subfertility Group trials register (2005年6月1日)、 Cochrane Controlled Trials Register (Cochrane Library Issue 2, 2005)、 MEDLINE (1996  June 2003)、 MBASE (1980年2005年6月) 以及文章的參考資料清單,並聯絡研究的作者以獲得遺漏或是未發表的數據。

選擇標準

有2位審稿者對這些試驗進行過確認,並且獨立地完成的篩選。當中收集了輔助胚胎孵化(在胚胎更換之前進行機械式、化學式,或是以雷射的方式來破壞卵透明帶)的隨機對照試驗,而比較的對象則是非輔助胚胎孵化之人工受孕,比較兩者之活胎臨床懷孕率或著床率。

資料收集與分析

共有2位審稿者獨立地完成了品質方面的評估,並擷取出資料。這些結果都以比率的型式來進行擷取,並且適當地,使用了隨機效果的統合分析、靈敏度分析、次群組與統合回歸等方式來加以合併。

主要結論

共有23份隨機對照試驗,當中包含了2668名婦女,報告結果有849次懷孕。跟對照組比較起來,若是選擇了輔助胚胎孵化時,在產下活胎率並沒有顯著的差異(CTs;OR 1.19 95% CI 0.81到1.73;於516名婦女中,有163個生產數)。經歷過輔助胚胎孵化的那些婦女們,很明顯地會更加臨床懷孕率(2 CTs,OR 1.33,95% CI 1.12到1.57)。在這2組當中,每1名婦女的流產比率都是差不多的(1 CTs OR 1.23,95% CI 0.73到2.05)。跟對照組中的婦女比較起來,那些被隨機分配到要接受輔助胚胎孵化的婦女們,在每1名婦女懷上多胞胎的比率方面,卻是增加的(CTs OR 1.83,95% CI 1.19 到2.83)。在臨床的懷孕比率方面,這些進步代表了某種意義,那就是任何1間診所的成功率若是達到了25% 的話,就有可能讓CPR的提升幅度到達28與39% 之間,而其中所有的項目都是均等的。若是要探討輔助胚胎孵化對於好幾種重要的結果方面有什麼影響,包括同卵雙胞胎,胚胎受損、先天與染色體異常及囊胚體外發育等,這些試驗並沒有提供充足的資料。

作者結論

儘管臨床上懷孕的可能性已經顯著地提升了,但是輔助胚胎孵化對於產下活胎的比率方面是否會有任何影響,仍然欠缺足夠的證據來確認。雖然說人們還是會顧慮到懷上多胞胎的比率變高了,但是如有推行單1胚胎殖入的政策,則可降低多胞胎比率。現階段看來,仍然欠缺足夠的證據來支持我們推薦輔助胚胎孵化。

翻譯人

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

對於那些始終無法成功地採用體外受精的婦女們而言,有某些證據顯示,輔助胚胎孵化可以增加懷孕的機會,但是還需要有更多的研究。輔助胚胎孵化是1種技術,有時候可以被用於進行體外受精(IVF)與類似流程的時候。它包含了讓受精卵外面圍繞之透明帶變薄的過程,或是在透明帶上面打出1個洞。這樣的方式或許能夠提高胚胎附著上子宮的機會,因此懷孕的過程就能夠開始。本篇回顧發現,對於那些始終無法成功地採用體外受精的婦女們而言,而且很有可能是針對那些比較年長的婦女們,某些證據顯示輔助胚胎孵化或許可以增加懷孕的機會。然而,針對報告中所提到的多胞胎比率,人們還是會顧慮到懷上多胞胎的比率變高了,而且仍然需要有更深入的研究。

Plain language summary

Assisted hatching of fertilised eggs to improve the chances of pregnancy in assisted conception (IVF and ICSI)

There is some evidence that assisted hatching improves the chances of pregnancy in women for whom IVF has been repeatedly unsuccessful, but more research is needed.

Assisted hatching is a technique sometimes used for IVF (in vitro fertilisation) and similar procedures. It involves thinning the coat surrounding a fertilised egg, or making a hole in it. This may improve the chances of the embryo attaching to the womb so that pregnancy can begin. The review of trials found some evidence that assisted hatching may increase the chance of pregnancy beginning in women for whom IVF has been repeatedly unsuccessful, and possibly in older women. However, the reported increase in the multiple pregnancy rate is of concern and further studies are needed.