When placed in the closed cervix, a osmotic dilator absorbs
moisture from the tissues surrounding the cervix and swells, opening the cervix
slowly and with little discomfort. Two common types of osmotic dilators are a
laminaria, a small tube made of dried seaweed, and
synthetic dilator, a man-made sterile, dry
Unless a woman is in labor before childbirth, the cervical
opening is very narrow. An osmotic dilator is commonly used to gently open the
cervix before a gynecologic procedure that requires the cervix to be open,
allowing access to the uterus and fallopian tubes. Cervical dilation reduces
the risk of injury to the cervix during such a procedure.
the cervical dilation with laminaria occurs in the first 6 hours. But maximum
dilation usually occurs 12 to 24 hours after the laminaria is placed. This means
that laminaria placement may be done the day before a procedure. Osmotic
dilators may be sequentially added to or replaced to increase the cervical
A synthetic dilator opens the cervix in less time and can
be used several hours before a procedure.
Sarah Marshall, MD - Family Medicine & Rebecca H. Allen, MD, MPH - Obstetrics and Gynecology & Kirtly Jones, MD - Obstetrics and Gynecology
The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.