No, this thickening of the uterine wall is not permanent.
If the egg gets fertilised, it begins to divide to form an embryo. The embryo gets embedded in the uterine wall resulting in pregnancy. During
pregnancy, no more eggs are released and the thickened lining is discharged only when the baby is born.
However, if fertilisation does not occur, the released egg and the thickened lining of uterus along with blood vessels are shed off that resulting in