Success Rates in IVF
What are my chances Doc?
"There are lies, damn lies and then statistics"
Benjamin Disraeli
One of the most difficult questions you will ask is what is the success rate of the unit that you plan to attend. It is one of the most important questions that you will want to know so why is it often so hard to get a straight answer?
The success of a IVF unit can be made to almost any number desirable. The honest answer is that most patients will fail to achieve a pregnancy than succeed -simple fact.
The problem arises as there are so many ways to represent the data
Pregnancy rate ( judged by positive pregnancy test or detection of fetal heart by ultrasound ) per stimulation cycle, per egg retrieval or per embryo transfer ?
e.g 200 IVF cycles with 35 deliveries
| 150 embryotransfer |  |
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| 175 egg collections | |
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| 200 IVF cycles | |
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| 17% | 23% | 23% | 27% | 30% | 33% | |
| 35 deliveries |  |
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| 40 advanced pregnancies | |
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| 45 clinical Pregnancies | |
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| 50 positive pregnancy tests | |
Another point to concider is the policy and patient population of the IVF unit:
Patient selection
Individuals have widely ranging pregnancy likelyhoods and units with a higher number of women over ,lets say 38 years of age, will have a lower total pregnancy rate.
Cancellation
By canceling patients with poor ovarian response will increase the total pregnancy rate
Number of embryo transferred
Number of fresh embryos transferred is one of the most simplest ways to increase pregnancy rate.
It should not be the aim of the media to report great advances in reproductive medicine as the information can be misinterpreted and lead to false hopes.
More often than not a new method is only applicable a select population of patients.
| HFEA National Livebirth Data 2000-2001 | <38 | all ages |
| All IVF/ ICSI Cycles Started | 25.1% | 21.8% |
| IVF+ICSI per ET | 28.9% | 25.4% |
| Frozen embryo per ET | 16.9% | 14.7% |
Recently in the media the transfer of embryos at the blastocyst stage has been reported with high success rates-but this is not applicable to all patients as some patients after electing to wait for the embryos to develop to blastocyst stage have no embryo transfer at all!
| No. patients | Embryotransfers | Positive pregancy tests | Pregnancy rate | Actual pregnancy rate |
| 100 | 100 | 40 | 40%(40/100) | 40% |
| 100 | 60 | 40 | 66%(40/60) | 40% |
It is advisable to discuss the suitability for blastocyst transfer as many units may recommend transfer at the blastocyst stage if there are many oocytes collected or if previous IVF attempt have been unsuccessful with good quality embryos.
A couple who have undergone several unsuccessful IVF attempts may be more willing to accept an IVF attempt with no embryo transfer at the end of their treatment.
The literature reports take home baby rate as 20% and is accepted that success after IVF largely depends on the age of the women with pregnancy rates dropping after the age of 40 to less than 5%
How are you best to be advised then? Choosing a clinic
The answer is not easy and cannot be reduced to just a number but as in many things look for long and extensive experience, innovation and compassion.
Review the general reputation of the professionals and learn as much as you can. Talk to friends and finally trust your own judgment.
