During natural delivery, the vagina should let the fetal head with the diameter of 10 cm pass through, and the vaginal sphincter will expand and rupture to the maximum extent, so that the vagina will be relaxed to varying degrees.

Of course, but this does not mean that natural childbirth is the culprit of vaginal relaxation.

Because the pelvic muscles and ligaments of pregnant women will be fully stretched during labor, preparing for the birth of the baby. Therefore, even if caesarean section is adopted, the vagina will be relaxed.