Fetal reabsorption and lethal homozygous varieties

I was thinking about a few lethal homozygous breeds, and how some are born, and die off after birth, and some are absorbed before birth. I'm wondering what the long term health issues might be, in the varieties which absorb the homozygous mice before birth?

Does the process damage the reproductive organs at all? Could this have to do with the fertility issues found in some of these varieties?

Just a passing thought.

Whether it's related to fertility issues would depend on which fertility issues you're referring to. It's related to small litter sizes, and occasionally entire reabsorbed litters. Depending on the variety, the gene will be lethal at different stages of development, and that would make a huge difference.

In general, spontaneous abortion early in the development of a fetus is perfectly normal. It happens so often in humans that most women don't even find out they were pregnant. With earlier pregnancy tests, we're actually doing a lot of emotional damage to women who find out they're pregnant, only to have the embryo spontaneously abort within the first six weeks. Increasing the rate of something that already happens at a fairly high rate should make no difference in the reproductive health of the doe. Later spontaneous abortions, however, would make it more difficult to absorb the fetus. If the variety doesn't have an increased chance of birthing dead fetuses, you could assume that the fetuses are being reabsorbed at an early enough date. That said, it's pretty hard to tell if a doe is birthing stillborns, since she'll just consume them as quickly as possible, leaving no evidence.

You can find out generally when each variety aborts its homozygous-lethal young fairly simply, between JAX and other research papers.