Searching around the web, it looks like most miscarriages are due to aneuploidy. That would be easy to detect and select against.
It’s hard to find good numbers for the human mutation rate. I saw numbers ranging from 42 to 200 per generation. Sperm seem to have more mutations than eggs on average. It can vary based on environmental exposure to mutagens, and older parents tend to have more mutations on average. Perhaps embryonic parents simply wouldn’t have the time to accumulate many mutations. On the other hand, one has to do unnatural things to get these embryonic cells to turn into gametes. If any of these steps are mutagenic, then the mutation rate could be even worse.
Searching around the web, it looks like most miscarriages are due to aneuploidy. That would be easy to detect and select against.
It’s hard to find good numbers for the human mutation rate. I saw numbers ranging from 42 to 200 per generation. Sperm seem to have more mutations than eggs on average. It can vary based on environmental exposure to mutagens, and older parents tend to have more mutations on average. Perhaps embryonic parents simply wouldn’t have the time to accumulate many mutations. On the other hand, one has to do unnatural things to get these embryonic cells to turn into gametes. If any of these steps are mutagenic, then the mutation rate could be even worse.