Chlamydia and Infertility

Chlamydia Background information

Chlamydia is a common sexually transmitted infection (STI) caused by the bacterium, Chlamydia trachomatis. Chlamydia infection is extremely common. Chlamydia is the most common sexually transmitted infection in the United States. The Center for Disease Control estimated that 2.8 million Americans are infected with chlamydia each year.

Chlamydia can be transmitted during vaginal, anal, or oral sex. Chlamydia can also be passed from an infected mother to her baby during childbirth. Any sexually active person can be infected with chlamydia. The greater the number of sex partners, the greater the risk of infection.

About 75% of infected women and about 50% of infected men have no symptoms of chlamydia infection. If symptoms do occur, they usually appear within 1 to 3 weeks after exposure. Women who do have symptoms might have an abnormal vaginal discharge or a burning sensation when urinating. If the infection spreads from the cervix to the fallopian tubes some women still have no signs or symptoms; others have lower abdominal pain, low back pain, nausea, fever, pain during intercourse, or bleeding between menstrual periods.

Chlamydia can cause infertility

In women, untreated infection can spread into the fallopian tubes and cause the tubes to become blocked at the very ends. This is known as hydrosalpinx. They can also develop scar tissue around the fallopian tubes that makes it more difficult for the tube to “pick up” the egg at the time of ovulation. The problems can lead to infertility and an increased risk for ectopic (tubal) pregnancy.

Distal tubal obstruction can be detected by performing a hysterosalpingogram. Pelvic adhesions , however, can only be detected by undergoing a surgical procedure to look inside of the abdominal cavity. This is usually done using a technique called laparoscopy where a fiber optic telescope is inserted through the belly button under general anesthesia. Since laparoscopy is a much more invasive procedure, it is desirable to avoid it whenever possible.

Blood tests to detect tubal damage from chlamydia

The most common test to detect chlamydia infection in women involves taking a swab from the cervix during a speculum exam in the doctor’s office. The swab is tested for chlamydia DNA. The problem with this test is that it does not tell the physician how long the infection has been present, how severe the infection is and whether the woman with the infection has sustained tubal damage. The swab test can also miss an infection that has moved up into the uterus or tubes and is no longer in the cervix.

Blood tests can also be performed to detect the antibodies the body makes when exposed to the chlamydia bacteria. These blood test are fairly predictive for finding women with tubal damage during laparoscopy. A recent study found that the presence of the chlamydia antibody predicted the presence of tubal damage (blockage or adhesions )correctly 62% of the time. Conversely, the absence of the chlamydia antibody predicted the absence of tubal damage 90% of the time.

It is important to note that the presence of elevated levels of chlamydia antibody does not necessarily mean that a woman has an active chlamydia infection. It simply indicates that she was exposed to the bacteria. In fact, it is estimated that, if left untreated, about 45% of infected women without symptoms will clear the bacteria from their bodies. In women who clear an infection rapidly, the risk of tubal damage may be low. On the other hand, persistent exposure may result in chronic inflammation and may increase the risk of tubal damage.

Another blood test that may be useful is called the C reactive protein (CRP). For many years, CRP was known as a highly sensitive but non-specific marker for acute inflammation. It is produced in the liver and rises to very high levels within 4-6 hours following acute injurious conditions such as trauma, surgery, or infection. More recently, researchers have developed a more sensitive test called hsCRP (highly sensitive CRP). with this new test, it is now possible to measure conditions indicative of chronic, low grade inflammation.

A recent study has found that combining the chlamydia antibody test and the hsCRP increased the chance of finding tubal disease to almost 90%.

Treatment of chlamydia for infertility

Chlamydia can be easily treated and cured with antibiotics. Her partner should be tested and treated. The couple should abstain from sexual intercourse until they have completed treatment, to prevent reinfection. Having multiple infections increases a woman’s risk of infertility.


This is an important study. Laparoscopy is not a benign procedure. It is a surgery that requires general anesthesia and carries the same risks as any surgical procedure. It is very desirable to have a way to predict ahead of time which women are likely to benefit from laparoscopy and which women are unlikely to benefit. It appears from the results of this recent study that we can predict accurately about 90% of the time.

Women who have elevated levels of the chlamydia antibody and hsCRP should be given the option of having a laparoscopy as part of their infertility evaluation.