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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Bag of membrane ruptures:
assistant
The correct answer is  Membranes usually rupture after full dilatation of cervix or sometimes even beyond, in the second stage.
Early Rupture of Membranes:

Rupture of membranes any time after the onset of labour but before full dilatation of cervix.

Premature Rupture of Membrane:

Rupture of membranes before the onset of labour.
Sometimes the membranes remain intact until completion of delivery, the fetus is then born surrounded by them and the portion covering the head of the newborn infant is known as the Caul.