Is it possible to go from 2cm dilated and 80% effaced to 1-2 cm and 0% effaced and very posterior all in less than 24 hours?

Every woman is different, and so it is difficult to say whether this would be possible. We are not a medical consultancy and so it is advisable that you see a doctor or medical professional, for an expert opinion on this issue. It would probably be very extreme for a woman to go from being 80% effaced to 0% effaced in 24 hours without any dilation at all.

• Effacing

Effacing happens when the mucus plug at the bottom of the cervix comes out and is passed through just before you have a baby. The cervix then becomes shorter, and this is called effacing. It should not be possible to become less effaced before you have the baby, because the cervix being shorter, or more effaced, helps the baby to come out quicker.

• Cervical dilation
  

Effacement is then followed by cervical dilation, which is where the vaginal opening becomes wider to let the baby out. Because of this, it is pretty impossible to become less effaced and possibly less dilated at the same time, as effacement will not reduce until after the baby is born.

If you mean after the baby is born, it would still be pushing it to become hardly effaced at all and completely not dilated. After a woman has had a baby, it can take at least a few days for everything down there to go back to normal again, and it can take weeks before the bump completely goes.

• Talk to a doctor
  

If you are unsure about anything to do with pregnancy, talk to a doctor. They can advise you on the best thing to do and are better placed to give advice in this field. Another option is to ask an online doctor site, as they may also have a better idea of how to answer this question.