How can the fertility decline curves of these two women ever be the same or even similar?

[Petite_girlie]

Woman A :

Drinks alcohol and /or smokes

Has had multiple partners thereby exposing her to STIs which are the biggest damage to the reproductive system

Regularly takes contraceptives which interfere with the natural hormones of the body

Has had generations of first degree relatives with similar lifestyles so more likely to have accumulated DNA damage

Woman B who has never had alcohol, contraceptives, partners and any such relatives

I hope they conduct a study to observe these dramatically different groups and quantify the differences.

[Boromir]

Because fertility might be much more robust than you think in normal 'relative' healthy people. All the things you cite can have a limited effect on a woman's fertility, but the statistics only mention 'how many kids per woman', not how many months of unprotected sex she needed to get pregnant. In addition, there is no correlation with the male factor, maybe she'll have younger partners that have better sperm, and get pregnant faster than a similar situation with a very healthy couple.

There are too many unaccounted parameters for to be able to make a precise assessment. Pretty much like the scene from the beginning of Ideocracy where they compare the offspring figures of a typical redneck and a highly educated couple of rich yups.

[sportsman_MD]

Many other variables contribute to fertility decline. You didn’t give any details about Woman B genetically, so there definitely may be something there. Also, there are plenty of other environmental factors that contribute to fertility decline.

[MasterKS]

because Woman A is made up bad woman, its medical mafia, anyone can gets fertility decline for various reason no need of only STI, multiple partner, contraceptives.