When we talk about IVF success rates, it’s important to know that success isn’t defined by just one moment. Instead, it’s a journey, much like climbing a mountain. Imagine the IVF process as a climb toward the summit. Along the way, there are different stages, just like there are points on the mountain before reaching the peak.
- At the base of the mountain, we start with ovarian stimulation, helping your body produce eggs.
- Next, we reach the middle stage with egg retrieval, where we collect the eggs.
- Some continue on to the embryo transfer stage, higher up the mountain.
- Finally, reaching the summit, we achieve the ultimate goal — a live birth.
Each stage has its own unique challenges, just like climbing the mountain, and each step is important when we talk about IVF success rates.
Understanding the Numerator and Denominator
Success rates are always measured as a fraction with a numerator (the end result, like a live birth) and a denominator (the starting point, like the initiation of ovarian stimulation). The most accurate way to measure IVF success rates is to focus on live birth rates (numerator) because a positive pregnancy test doesn’t always lead to a live birth.
But the denominator (starting point) can vary and be more complicated. Sometimes success rates are reported based only on patients who have reached the embryo transfer stage (live birth rates per embryo transfer, or per PGT-A tested embryo), but not everyone who begins an IVF cycle will make it to this stage. So, while success rates per embryo transfer may sound impressive, they don’t always reflect the full journey.
Cumulative Live Birth Rate: The Most Accurate Measure
To get the clearest picture of success, it’s important to look at the cumulative live birth rate per initiated cycle. This metric counts everyone who begins an IVF cycle, not just those who make it to embryo transfer. It shows the percentage of patients who reach the summit (live birth) starting from the base of the mountain (initiating ovarian stimulation). This gives a fuller, more realistic view of the success you can expect when you begin IVF treatment.
