According to a 2018 article from the ASRM, research consistently shows that smoking half of a pack of cigarettes a day reduces fertility in females.
The negative effects of smoking on fertility may increase in relation to the amount people smoke.
In some cases, research found that certain negative effects on fertility only occurred in females who smoked more than 20 cigarettes each day. However, overall, there was a link between smoking and infertility for all levels of smoking.