Culdocentesis is a procedure that checks for abnormal fluid in the space just behind the vagina (cul-de-sac).
How the test is performed
First, you will have a pelvic examination. Then, the health care provider will grasp the cervix with an instrument and lift it slightly.
A long, thin needle is inserted through the wall of the vagina (just below the uterus). A sample is taken of any fluid found in the space. The needle is pulled out.
How to prepare for the test
You may be asked to walk or sit for a short time before the test is done.
How the test will feel
You may have an uncomfortable, cramping feeling when the cervix is grasped. There is a sharp, brief pain as the needle is inserted.
Why the test is performed
This procedure is done when you have pain in the lower abdomen and pelvis, and other tests suggest there is fluid in the cul-de-sac. This test may also be done when the doctor suspects a ruptured ectopic pregnancy or ovarian cyst.
The test is rarely done today because an ultrasound can usually detect fluid in the cul-de-sac.
No fluid in the cul-de-sac, or a very small amount of clear fluid, is normal.
What abnormal results mean
Even when no fluid is found, it may be present, and you may need other tests. If fluid is drawn, it is cultured to see if you have an infection. If nonclotting blood is found in the cul-de-sac, you may need emergency surgery.
What the risks are
- Puncturing the uterine or bowel wall
You may need someone to take you home if you were given a sedative.
Culdocentesis is done very infrequently because a diagnosis can often be made with pelvic ultrasound.
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine.