Success of treatment

Though success rates vary, treatment does not carry any guarantee of success.  As with natural conception, the chances of pregnancy are closely linked to the mother’s age. There is no treatment for egg quality (due to age) – egg donation is sometimes the only option for women with poor ovarian reserve.

IUI 
Intrauterine insemination – IUI (artificial insemination using partner’s sperm) is used occasionally for the treatment of male infertility but is again is unlikely to be useful if a significant sperm abnormality is present.  Randomised controlled trials show that intrauterine insemination is better than timed intercourse for the treatment of male infertility, particularly when used with ovarian stimulation. Nevertheless, success rates of only 5–10% per cycle are reported in most studies when IUI is performed for male fertility.

IVF
For women aged 35 years and under, the success rate for IVF is currently around 45% per cycle of treatment. For 40-year-old women, the success rate is around 20%; and less than 10% for women aged over 42 years. 

IVF with ICSI
The chance of pregnancy per embryo is similar after ICSI or conventional IVF. Extra embryos arising from assisted fertilisation that are of good quality can be frozen for later use.  Clinical pregnancy rates of 30–40% per cycle are usual with micro-injection so long as there is good fertilisation and the woman is aged less than 40.  In a well-established programme, over 95% of couples will have at least one oocyte fertilised and the chance of pregnancy, per embryo, is at least as high as with conventional IVF for other types of infertility.