Cervical effacement and dilation

Cervical effacement and dilation

During the first stage of labor, the cervix opens (dilates) and thins out (effaces) to allow the baby to move into the birth canal. In figures A and B, the cervix is tightly closed. In figure C, the cervix is 60% effaced and 1 to 2 cm dilated. In figure D, the cervix is 90% effaced and 4 to 5 cm dilated. The cervix must be 100% effaced and 10 cm dilated before a vaginal delivery.

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