The adverse health effects of smoking are well documented and the information available is extensive. Likewise, there is a clear relationship between smoking and reduced female fertility.
The finding of nicotine and cadmium in the follicular fluid of female smokers demonstrates that all of these toxic substances in tobacco have access to the oocytes. It has been shown that the average time required to achieve pregnancy is longer in women smokers than in non-smokers. Furthermore, it is clear that smoking during pregnancy is associated with complications during pregnancy, including miscarriage, placenta previa, premature rupture of membranes, premature delivery and low birth weight of the newborn.
For all these reasons, the ideal for a woman seeking pregnancy is to quit smoking as soon as possible. The deleterious effect on the eggs will not be recoverable, so that, if assisted reproduction techniques are required, the number and quality of the eggs obtained will most likely be lower than what would correspond to a woman of the same age.
However, there are studies that postulate that smoking also has an effect on endometrial receptivity. It is possible, although there is no clear evidence, that this effect can be reversed by quitting smoking, so it would make sense to stop smoking at least one cycle before you start looking for pregnancy.
What is clear is that once pregnant, smoking should be avoided as much as possible, in order to facilitate proper placentation and not expose the baby to risks.