What is the Cumulative Probability of Pregnancy?
By Francis Polansky, M.D.
If you do just one cycle of IVF treatment, and if there are no "extra" frozen embryos available for subsequent transfer(s), you will have only one chance at pregnancy. Your probability of a successful treatment outcome (live birth) will be a per cycle probability.
IIf you do just one cycle of IVF treatment, and if there are no "extra" frozen embryos available for subsequent transfer(s), you will have only one chance at pregnancy. Your probability of a successful treatment outcome (live birth) will be a per cycle probability.
The cumulative pregnancy probability is not arrived at by simply adding up per cycle probabilities. If for example, your per cycle pregnancy probability was 40% and you decided to do three cycles of treatment, you will not have a 120% probability of a baby!
Once the per cycle pregnancy probability can be estimated, it is possible to calculate the cumulative pregnancy probability of two or more cycles of treatment.
The picture above illustrates a cumulative probability of three cycles of treatment: In this example, the per cycle probability of a successful outcome is 40%.
Let's imagine there are a hundred couples who were all told they have a 40% probability of a baby if they do one cycle of IVF. If all these couples plan to do just one IVF procedure (and no more regardless of the outcome), 40 couples will end up with a baby (per cycle probability of 40%).
If the same hundred couples (40% per cycle probability) plan to do a second IVF procedure if the first one was not successful, 58 couples will, in the end, have a successful outcome (cumulative probability of 58%).
If these same couples plan to do up to three cycles of IVF if the first two were not successful, 71 couples will have a live birth (cumulative probability of 71%).
At the time of your initial consultation at Bay IVF, I will generate a document showing your current, personal cumulative probability of a live birth for your recommended treatment(s). This can be a great tool in deciding how many treatment cycles to plan for.