Home > Medical Reference > Patient Education

Ask Our Experts

Get answers to your specific medical questions from UM Medical Center experts.

Note: This is for informational purposes only. Doctors cannot provide a diagnosis via e-mail.

 

Related Content

Our Doctors

Speciality Services

Podcasts

Vasectomy and vasovasostomy

Description

An in-depth report on vasectomy as a method of male birth control and reversal surgeries.


Unexpected Pregnancy

Pregnancy rates after a vasectomy are estimated to be very low, about 1 in 1,000. There are two main reasons for an unexpected pregnancy:

Residual Live Sperm and Resuming Sexual Activity

Once the patient feels comfortable, he can resume sexual activity, usually in about a week. During ejaculation, the patient may experience some discomfort in the groin and testicles at first due to the contraction of the vas deferens. This almost always diminishes as the tissues heal.

However, after the operation there are always some active sperm left in the semen for several months so the risk for pregnancy persists. It is essential that the patient and his partner continue to use other methods of birth control until his sperm count is zero. The patient is considered sterile only when there are no live or moving ( motile ) sperm in his semen. It takes, on average, around 3 months or 20 ejaculations to clear the viable sperm from the reproductive system, but it may take some men as long as 6 months to become sterile.

About a third of men experience a recurrence or persistence of sperm that have no ability to move ( immotile ) 12 weeks after surgery and, in one study, about 7% had persistently immotile sperm. Immotile sperm, however, cannot swim up the vaginal canal and pose no danger for fertility. In rare cases, vasectomies have to be repeated because live sperm persisted in the semen. The risk for sperm surviving indefinitely is, however, very low.

Recanalization

The primary reason for vasectomy failure itself is recanalization -- when the cut ends of the vas deferens spontaneously reconnect. Recanalization in some cases may be due to sperm granulomas. These are tiny balls of debris that form from sperm, scar tissue, and white blood cells at the incision site. Cells lining the inside of the vas deferens grow through the scar tissue and form a new channel through which the sperm can now move. In general, surgeons can reduce the risk for recanalization by leaving a gap between the two cut ends.

This natural vasectomy reversal can occur after any vasectomy surgical procedure, but it is uncommon, with most studies reporting it occurring in less than 1% of cases. When recanalization does occur, sperm counts are almost always very low and pregnancies are still rare. Most cases of recanalization develop within several months after the operation. In very rare cases (about 0.6%), sperm have reappeared a year or even longer after vasectomy.


A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com