In fact, it is impossible to determine whether it affects the production only by visually measuring the width of women's crotch from the outside. The scientific method of measuring pelvis is not the visual width, but usually the diameter of pelvis. The pelvis has two diameters in structure. Short anteroposterior diameter and wide left and right diameter are beneficial for the fetus to pass through, while long anteroposterior diameter and narrow left and right diameter are difficult for the fetus to deliver.
There is also a saying that after a woman gives birth, the pelvic seam will be opened and the hip bone will be widened. This statement is also one-sided. During pregnancy and childbirth, the pelvis will enlarge and the joints and ligaments will relax. But if you exercise properly after delivery, the pelvis will recover soon. The widening of hip bone is not the result of childbirth, but the lack of exercise leads to the enlargement of pelvis and out of shape.