embryos and eggs

Is the first sentence natural? Can you say that it is more successful to do that than this?

Can you say 'pregnancy to stick'?

It's more successful to freeze embryos than unfertilized eggs. There is a better chance of a pregnancy to stick if you freeze an embryo than an egg and go from there.

Is this sentence natural?
If you know who you'd like to be the father of your child or children, your eggs can be fertilized and frozen as embryos.

Thank you !!!