What is the success rate of insemination?
The success rate of IUI, IFI and IPI varies considerably between infertility clinics and in the same clinic between different couples. Success rates are in the region of 5-30%. Data from the Human Fertilization and Embryology Authority in the United Kingdom in 2006 found that IUI has a success rate of around 15% for each cycle of treatment.Over 50% of women aged under 40 years will conceive within 6 cycles of intrauterine insemination (IUI) of those who do not conceive within 6 cycles of intrauterine insemination, about half will do so with a further 6 cycles (cumulative pregnancy rate over 75%). [NICE guidelines 2013].
What are the factors that affect success rates?
Cause of infertility
The cause of infertility is crucial in determining the success rate of any treatment undertaken.
Male factor infertility
It has been reported that in male factor infertility, unstimulated (natural cycle) IUI increases the likelihood of pregnancy two-fold while stimulated IUI increases it by about five-fold. Men with severe sperm problems are not suitable for IUI because of the very low success rate.
In unexplained infertility, unstimulated IUI increases the likelihood of a pregnancy by three-fold, while stimulated IUI increases it by about five-fold.
The female partners fertility
Women with healthy Fallopian tubes and who ovulate regularly have a higher chance of achieving a pregnancy than women whose tubes are not healthy or do not ovulate regularly.
The female partners age
The younger the woman’s age the higher the chance of conception.
Duration of infertility
The chance of conception decline with the longer period of infertility.
The sperm quality and quantity, the degree of sperm motility, the percentage of normal looking sperm and the number of sperm are the most important factors. These may be assessed with a semen analysis.
It is generally accepted that re-evaluation and discussion about other form of treatments such as in-vitro fertilization (IVF) and gamete intra-Fallopian transfer (GIFT) should be carried out with the couple after 6 consecutive failed treatment cycles.
How many treatment cycles should be done with insemination?
The chances for success per month drop off after about 3 attempts and drop considerably after 6 months. About 90% of patients who conceive by IUI will do so in the first 6 cycles. If patients have not conceived after 6 cycles of donor or partner insemination, despite evidence of normal ovulation, tubal patency and semen analysis, a further 6 cycles of unstimulated intrauterine insemination before IVF is considered (NICE Guidelines 2013).