Success rate of IVF treatment
(pregnancy rate)
How successful is IVF treatment?
Since the birth of Louise Brown in 1978, there has been a worldwide steady improvement in success rates of IVF treatments. However, recent data from ESHRE 2011 of the European IVF Monitoring for 2008 appears to have levelled off. The overall pregnancy rate per transfer following IVF was 32.5% and following ICSI 31.9%. Both these rates were slightly lower than those of 2007.
The pregnancy rates vary between IVF clinics, and from time to time within the same clinic. The success of individual IVF clinics may be found in league tables published by HFEA. The overall live birth rate per treatment cycle is about 20%. There are many factors that may affect success rates.
The overall live birth rates for IVF in the United Kingdom have improved from last year from 20.4%. to 21.6%. Overall 23.6% of IVF births resulted in either twins or triplets (HFEA 2006). The success rates are remarkable if compared with the chances of spontaneous conception, which for many couples is very low and for some is zero.
Approximate chances of success of IVF treatment in women aged 38 years or younger in relation to the main steps of the IVF treatment are as follows:
| Ovarian stimulation | 90-95% |
| Collection of the eggs | 99-99.7% |
| Fertilization of the eggs | 90-97% |
| Normal embryo cleavage (division) | 94-98% |
| Implantation rate per embryo | 10-25% |
Why my IVF cycle failed?
One of the hardest things for an infertile couple to deal with is the failure of an IVF cycle. Indeed, the fear of failure often puts off a lot of infertile couples from even attempting another IVF cycle. For most unsuccessful IVF treatments, the cycles appear to have gone well, sufficient number of eggs, good fertilization and easy transfer of good quality embryos. The questions always arise as to why it did not work, and whether further investigations are needed prior to a subsequent IVF cycle, and whether emotional distress such as tension, worry was a contributing factor to their lack of success with their IVF treatment. Dr Boivin and colleagues from UK (BMJ,2011) did not observe any significant association between pre-treatment emotional distress and treatment outcome with assisted conception treatments. In general, there is no apparent reason for IVF failure.Recurrent embryo implantation failure is defined as the absence of a positive pregnancy test after three consecutive transfers of good quality embryos
What is the plan for my next IVF cycle?
- If ovarian response was poor - assess ovarian reserve, and increase the dose of FSH for the next cycle or use different stimulation protocol. Your specialist may also recommend taking DHEAS tablets 25 mg three times a day for three month prior to starting your IVF. there were no evidence of improved outcome for live birth when Human growth hormone was used for poor responders (RBM online Digest 2019)
- If sperm quality was poor or there was a poor fertilization rate - ICSI is recommended.
- If endometrial development was suboptimal (too thin or too thick) - investigate the cause and correct before the next cycle.
- If embryo transfer was difficult - the cervix can be stretched under a general anaesthestic early in the next treatment cycle. Alternatively transmyometrial embryo transfer or ZIFT may be employed.
- If there is significant hydrosalpinx - remove or clip the tubes before next cycle.
- If the couple has suffered recurrent failures at IVF (defined as three or more failed IVF cycles) - a full investigation is recommended, particularly assessment of the immune system such as thyroid abnormalities, thrombophilia, increased level of circulating NK cells and elevated Th1:Th2 cytokines ratio. Nevertheless, the role of these abnormalities in recurrent failure of implantation is a matter of debate. Similarly, assessment of uterine blood supply is advocatd by some.
- Chromosomal abnormalities can cause embryos to fail, even though they may look healthy. Embryologist in a standard IVF practice can not differentiate between chromosomally normal and aneulpod eggs or embryos under a microscope. Array comparative genomic hybridisation (CGH) enables scientists to analyse chromosomes and transfer only the healthiest embryos, increasing the chance of a successful pregnancy. The technique adds a substantial extra cost on the top of the usual IVF cost.
- Endometrial scartching. Scratching the lining of the endometrium about 7-14 days prior to IVF treatment have been demonstrated in some study to improve the likelihood of embryo implantation. Endometrial scratch is a simple procedure involve using a hysteroscope or pipple a. To date, the mechanism behind the success remains unknown. Furthermore, it is unclear how long this effect is expected to last. Dr Lenson and colleagues from New Zealand conducted a large, randomised study published in New England Journal of Medicine 2019 and reported that endometrial scratching before in vitro fertilisation does not increase live-birth rates. Additionally, subgroup analyses did not identify any populations of women who might benefit.
- Researchers have reported finding endomeriosis in women with unexplained infertility and IVF failure and up to 75% conceived after surgical treatment (Litman et al 2007)
Is there is a maximum number of failed IVF cycles after which the IVF center recommend to stop?
NICE guidelines in the United Kingdome recommend three NHS treatments cycles, but some NHS trusts offer less than this. Assuming there is no financial constrains, there is no set cut off if you go private although doctors should advise the patient to stop at some point if he or she feels the odds of success are too low to merit continuing treatment. Approximately 60% of IVF centers would recommend stop IVF treatment after two or three failed attempts. Some centers recommend stopping IVF treatment after 5 failed cycles. Few IVF centers do not have limits to the number of IVF cycles.
Spontaneous pregnancies following discontanuation of IVF and ICSI treatment
Marcus et al reported an overall cumulative pregnancy rate over a 6 year period following cessation of treatment was 29%. Eighty two percent of conceptions occured within two years. Positive factors associated with spontaneous conception were unexplained infertility, ovulation dysfunction, infertility less than four years and less than 4 IVF treatment cycles.(2016 Human Fertility)