The egg is the second genetic material required for conception. And while the man is gifted with millions of sperm per ejaculation during his life, a woman has already been given since her embryonic days with a very limited number of eggs. As you can see in the diagram above, a female fetus starts during embryonic life with about 4 million eggs, half of which are lost shortly before birth through the apoptotic mechanism. The decline of ovarian reserve count continues as age progresses and eventually the average woman uses approximately only 400 eggs by the age of 43. Technically this means that the eggs have the same age as the woman, and as observed the remaining eggs after the age of 42-43 have really fragile and defective genetic material that in fact may lead to genetic abnormalities of embryos and therefore miscarriages
