Also, the extent of permanent physical change varies greatly from person to person, often even from pregnancy to pregnancy for the SAME person. To take the most obvious example, caesarians are more invasive and more scarring than vaginal delivery (though I understand medicine has come a long way in reducing caesarian scarring over the past few decades.) It is not as if every women who ever gave birth was permanently disfigured, and fixating on the stories of those who were is like saying, "I will NEVER drive, because everyone who does gets in a disfiguring accident; just look at these testimonials!"

Yet even if that perspective were accurate, the list of hot octagenarians is vanishingly small; if your concern is losing your looks all I can say is "make your peace with it, because it will happen sooner or later whatever you do or do not." The only thing avoiding pregnancy to preserve ones appearance does is ensure that by the time ones body starts to deteriorate it will be too late to have kids.

That is not to say there is anything wrong with deciding against childbearing, only that big irrevocable decisions should be based on the best data.