Factors affecting the success of the treatment include the woman’s age, how long efforts have been made to conceive, and the couple’s overall situation, that is, the cause of infertility.
For insemination treatments, the probability of success per attempt varies from 15 to 20 percent.
With IVF and ICSI, the probability of pregnancy for women under 40 years of age is 35–45 percent per embryo transfer. However, in about one of five cases where pregnancy begins, a spontaneous abortion occurs in the early stages of pregnancy. In women over 40 years of age, the probability of pregnancy after embryo transfer is 20–30 percent. One in three pregnancies ends in a spontaneous abortion.
In most treatments, we can transfer one embryo at a time. This keeps the risk of twin pregnancy low at 4–6 percent. About one in four embryo transfers using frozen-thawed embryos results in a pregnancy. The probability of a pregnancy leading to a live birth is about 20–25 percent per embryo transfer.
This means that about half of couples under 35 years of age will have the child they are hoping for.