What are the Chances of Success with IVF?

Everyone considering IVF clearly needs to know the success rates achieved by the program they plan to work with. And yet correctly estimating a particular couple's chances is quite difficult due to the many variables involved such as age, cause of the infertility, health of the woman's uterus and so on.

The woman's age often has the greatest influence on the chances of success. This is because of the decline in both the number and quality of eggs that occurs over time. The figures below indicate the success we have had with IVF in couples where the woman's uterus was normal. Uterine abnormalities and autoimmune issues can reduce the effectiveness of IVF and unfortunately so can cigarette smoking which damages or kills eggs. Blocked fallopian tubes swollen with fluid (hydrosalpinx) can reduce IVF success rates by one-half, unless first removed surgically. Therefore in individual cases the averages below may not apply.

Woman's Age: Viable Pregnancy Rate:

• Less than 30:  60–65% per IVF Cycle
• 31–35:  50–55%
• 35–39:  33–40%
• 40–41:  20–25%
• 42–43:  15%
• 43–44: <5%
• 45:  0% "

One of the great difficulties with IVF is that is very hard to know when to stop. Throughout this discussion we have been talking about success in terms of percentages and probabilities. We can not with certainty predict who will ultimately succeed with IVF and who will not. A poor prognosis patient may conceive in her first IVF cycle and a supposedly good prognosis patient may still be unsuccessful after their third or fourth cycle. Random chance (plain old luck) has a lot to do with how soon success will come. Clearly though there must be a point at which we can no longer blame bad luck for continued failure. We obviously don't know everything there is to know about fertility and there are almost certainly a host of rare problems that may prevent successful embryo implantation. Finding this break point between chance and pathology is enormously important and is therefore the focus of a great deal of current research. The best evidence we have currently is that the point of diminishing returns is reached after IVF cycle number three or four. This applies to couples where IVF produces a reasonable number of good quality embryos for transfer. If, on the other hand, only unhealthy embryos result from the first IVF cycle then the chances of success are much lower than normally found and the couple may well consider stopping IVF at that point.