Smoking lowers the number of healthy eggs a woman has, and that too prematurely (younger women have more ovarian reserve than older women) Studies show that smokers can lose about 20% of their ovarian reserve compared to non-smokers. This means fewer eggs are available for fertilization, making it harder to conceive in the first place.Smoking lowers the number of healthy eggs a woman has, and that too prematurely (younger women have more ovarian reserve than older women) Studies show that smokers can lose about 20% of their ovarian reserve compared to non-smokers. This means fewer eggs are available for fertilization, making it harder to conceive in the first place.