Let’s say we have identical twins, Alice and Beth, who were in the same physical condition (same weight, general health) when they got pregnant five years ago at age thirty-five, three months after their birthdays.
Alice has been pregnant twice, giving birth to a set of twin boys at age thirty-six, and a second set of twin boys at thirty-eight.
Beth also has four sons now. But she gave birth to them one at a time, having one baby once a year from the age of thirty-six on.
And for fun, let’s also say all eight babies were about the same size, because Alice had bigger than average twins.
Alice and Beth are now forty. Which sister’s pregnancies are likely to have taken more of a toll on her body, the sister who had two sets of twins two years apart, or the sister who had a baby every year for four years?