The first population-based cohort study not surprisingly finds that ICSI offers no advantage over conventional IVF in live birth rate for couples with non-male factor infertility
The registry reports from ESHRE's EIM Consortium have made clear in the past years that outcome from ICSI treatment is no better - indeed even slightly worse - than from IVF. In its latest report (for 2013) the EIM found a clinical pregnancy rate of 34/5% per ET with IVF, and 32.9% per ET with ICSI. These rates were described as "stable".(1) EIM also showed - as it had for several years previously - that ICSI remains by far Europe's (and the world's) favoured method of fertilisation, whatever the indication, with around two ICSI cycles performed for every one of IVF.
The registry reports are dealing with total populations, irrespective of indication. But now, a new cohort study from Australia has looked at the use of ICSI in non-male factor treatments and again found no benefit in live birth rate for ICSI.(2) The results were based on the outcome of treatment in a cohort of 14,693 women having IVF and ICSI between 2009 and 2014 in the state of Victoria, Australia. Pregnancy and birth outcomes were recorded for the first oocyte retrieval (fresh stimulated cycle and associated thaw cycles) until 2016 or until a live birth was achieved, or until all embryos from the first oocyte retrieval had been used.
In line with uptake rates around the world, use of ICSI was far greater (8470 women) than use of IVF (4993 women), though over the study period the use of ICSI increased from 52.6% in 2009 to 65.9% in 2014 - while the proportion of couples with male factor infertility remained relatively stable. Not surprisingly too cumulative outcome in each group was no better or worse than the other (37.0% LBR for IVF and 36.0% for ICSI).
The trend to prefer ICSI over IVF in all cases of assisted reproduction has become something of a bete noir for authoritative opinion in ART. In 2012 the ASRM declared that "there are no data to support the routine use of ICSI for non-male factor infertility", while ESHRE - at least from the pen of one of its editors - noted that "we clearly overestimate the effect of ICSI".(3) The enthusiasm for ICSI, wrote Hans Evers, is "unjustified", its use in most non-male cases "unnecessary, ineffective and costly care".
But how to explain the trend? A Lancet report by Bhattacharya and colleagues in 2001 came at a time of proposals that ICSI was associated with higher fertilisation and implantation rates than IVF.(4) Such reports, said the authors, "have lowered the threshold for IVF, such that ICSI rather than conventional IVF should be considered the treatment of choice in all cases requiring assisted reproduction". Even though this study - as others and many reviews - found no benefit of ICSI over IVF in non-male factor infertility, the preferential trend for ICSI clearly continues. And this despite the warning from 2001 that "given the complex and more invasive nature of ICSI, adoption of such a policy would have wide implications for the future of IVF, with a major effect on use of resources and safety".
1. European IVF Monitoring Consortium. Assisted reproductive technology in Europe, 2013: results generated from European registers by ESHRE. Hum Reprod 2017; 32: 1957-1973.
2. Li Z, Wang AY, Bowman M, et al. ICSI does not increase the cumulative live birth rate in non-male factor infertility. Hum Reprod 2018; doi:10.1093/humrep/dey118.
3. Evers JLH. Santa Claus in the fertility clinic. Hum reprod 2016: 7: 1381-1382.
4. Bhattacharya S, Hamilton MP, Shaaban M, et al. Conventional in-vitro fertilisation versus intracytoplasmic sperm injection for the treatment of non-male-factor infertility: a randomised controlled trial. Lancet 2001; 357: 2075-2079.