As miraculous as IVF is, it's not without problems & heartache.
We miscarried on attempt #2, and were pregnant with twins on attempt #3 but lost one of the twins a few days before they were born.
And then when we thought we were all done having kids, we got pregnant on our own (which had never happened before), and then a couple of years later my wife said: "I want to try for one more" and I thought: "Yeah, sure, that will never happen" and then within a month she was pregnant again.