This is the advice of a priest to us that you should not try very hard in getting pregnant. There are cases where the pregnancy would prosper with the help of science but the baby would be abnormal. We actually tried 3 times but we stopped when we felt that we are not lucky to be given a baby.
I think this largely comes down to personal preference. I've spoken with a lot of couples who feel like it is just not meant to be if they're unable to get pregnant naturally, and of course I respect that decision. At the same time, fertility solutions such as IVF have given the dream of parenthood to many couples, who have gone on to give birth to healthy and normal babies. My philosophy is to look at all of your options, and do whatever makes you the happiest.
I don't think giving up after the third trial is the answer. I say keep trying until you are successful. My attitude is like if you don't succeed at first, try and try again.
It really depends on the woman, if she can still be pregnant or not through natural means. Science can really aid them if they can't via in-vitro fertilization.
I also agree with what Tyche is saying. I recently saw a story in the news of a 83 years old Woman from somewhere in India who gave birth to twins through science. So I guess having kids is getting easier and easier.
Our maid went through a situation where she neither had her own egg nor her womb was large enough.She is diabetic and has a thyroid issue. She went through the surrogacv process - can't even call it that - and tried umpteen number of times. The hospital could have told her. All what she got was a huge bill and a loan that she has yet to clear.