Pregnancy rate measures the percentage of IVF cycles that result in a pregnancy, while live birth rate measures the percentage of IVF cycles that result in a live baby. Live birth rate is considered to be a more accurate measure of IVF success because some pregnancies do not result in live births.
While comparing IVF success rates between clinics, it is important to consider which metric is being used. Pregnancy rate counts the number of pregnancies per 100 IVF cycles, while live birth rate counts the number of live births per 100 IVF cycles. Since not all pregnancies result in live births, live birth rate is considered to be a more accurate measure of IVF success.
What does effect IVF success rates?
IVF success rates? can be affected by a number of factors, including:
- Previous pregnancy: Couples who have had a successful pregnancy in the past are more likely to have success with IVF.
- Age: IVF success rates decline with age, especially for women over 35.
- Cause of infertility: Couples with certain infertility conditions, such as fibroids or endometriosis, may have lower success rates.
- Quality of eggs and embryos: The quality of eggs and embryos is essential for IVF success. Factors such as maternal age, ovarian reserve, and stimulation protocol can all affect egg quality.
- Number of embryos transferred: Transferring more embryos can increase the chances of pregnancy, but it also increases the risk of multiple births.
- Sperm quality: Male factor infertility can also affect IVF success.
- Donor eggs: Donor eggs can be used to improve success rates for women with poor egg quality.
- Controlled ovarian stimulation protocol: The stimulation protocol used to prepare the ovaries for egg retrieval can affect success rates.
- Embryo transfer: Embryo transfer is a critical step in the IVF process. Any issues with the transfer, such as incorrect timing or unexpected biological factors, can reduce the chances of success.
- Uterine receptivity: The uterine environment must be receptive to implantation in order for pregnancy to occur. Factors such as the thickness of the uterine lining, immunological factors, and the uterine shape can all affect receptivity.
- Lifestyle: Smoking, drinking alcohol, and being overweight can all reduce the chances of IVF success. Women undergoing IVF treatment are advised to stop smoking and drinking alcohol at least three months prior to starting treatment, and to maintain a healthy weight.
How to measure IVF success rates ?
IVF success rates can be measured in a number of ways. Three common measures are:
- Live births per started treatment cycle: This is the percentage of women who have a live birth from a fresh embryo transfer in their first treatment cycle. However, it does not include babies born from frozen embryo transfers.
- Pregnancies per embryo transfer: This is the percentage of women who become pregnant after a single embryo transfer. It does not count women who do not respond to ovulation induction or women who may later miscarry.
- Live births per embryo transfer: This is the percentage of women who have a live birth after a single embryo transfer. Multiple births, such as twins, are counted as a single birth for this measure.
Which measure of IVF success is most important depends on the individual patient’s circumstances and goals. For example, if a patient is primarily concerned with getting pregnant as quickly as possible, then pregnancies per embryo transfer may be the most important measure for them. However, if a patient is more concerned with having a single, healthy baby, then live births per embryo transfer may be the more important measure.
It is also important to note that IVF success rates can vary widely between clinics. Patients should carefully compare the success rates of different clinics before choosing one.