Why is my cervix not opening at 40 weeks?

The cervix is stiff and closed through most of pregnancy to hold your baby inside your uterus. But during labor, cervical dilation (widening) allows your baby to pass through your birth canal. Cervical ripening often happens on its own, naturally. Some women may benefit from assisted cervical ripening.

The baby has a large head. the baby is in a difficult position. contractions aren't strong enough and your cervix doesn't open (dilate) pelvis is too small to fit your baby through.