Success rates in IVF
Pregnancy rates can be affected by many factors. Among them are, age of the woman, factors involving male sperm
function (azoospermia, varicocele, etc), major illnesses in the patients' medical history, whether or not there
there are prior pregnancies and live births.
We receive phone calls and email messages asking about our success rates. The exact meaning of success rate should be specified. If the focus is on achieving pregnancy then the method to confirm pregnancy is crucial. A positive pregnancy blood test, a gestational sac and a fetal heart rate seen on ultrasound, or even life birth could all be considered criteria for success rate. Also when calculating the ratio, the denominator is significant, the value could be the number of patients who began IVF treatment or number of patients who have had an embryo transfer. Regulations govern the number of embryos transferred depending on the patient's age and number of IVF attempts. Patients over the age of 35 or who have had two IVF attempts can have 2 embryos transferred back into the uterus. When the embryos are good quality, the number of embryos are directly proportional to a successful pregnancy rate. Although some patients could benefit from supernumerary embryo transfers (e.g.low ovarian reserve), the regulations which only consider age allow only one embryo to be transferred. This and many other aspects are complicated and open to discussion but cannot be simplified into one number designated to be the success rate.
One should also consider the percentages of infertile couples who get pregnant after three or four attempts at IVF. These cases are rarely mentioned but the approach to their treatment, planning their IVF related expenses, application of prior clinical experience, and other parameters should also be taken in to consideration when evaluating the success rate of a clinic. These kinds of criteria, however, are not helpful when comparing different IVF centers.
In summary, when our patients are looking at different IVF clinics for treatment, they can inquire about the experience of the clinicians, how long he/she has been working in this field. They can also ask about how long the clinic has been runnning. Asking a clinic that has been actively treating patients for 20 years about their success rate is not useful.
Asking an IVF center about their success rates regarding factors that are specific to the couple is relevant. This will provide helpful information for couples starting treatment for a particular infertility disorder. For example in a situation where a woman who is 41 years old, has had 4 unsuccessful IVF attempts, low ovarian reserve with 3-5 eggs per retrieval, substandard semen parameters, is told they have a 50% chance of pregnancy, they should avoid that clinic. Patients should be told of their chances of getting pregnant based on information pertaining to their specific infertility disorder before going through unnecessary expense.