My coccyx, my lower back, my pelvis, my pelvic floor, my stomach muscles - I would definitely consider the effects of another pregnancy on my body and may well decide that 3 is enough times. Being pregnant takes its toll.
What about women who are pregnant and give birth 7, 8, 9, 10 times? Or even 20 times?
Do some people have a slightly easier time than others so don't feel so worn out by it? (I don't mean worn out emotionally, or tired, I mean my body can only stretch to the size of a small hotel and then expel something the size of a sofa through a hole the size of a nostril so many times).
Or do you get to a certain level of worn outness and then plateau?
Or are some people just absolutely knackered by repeated pregnancies? I am sure this must be true for some.
I'm thinking about both women who make the choice to have large families, and also women in developing countries who don't have much say in the matter.