Sexually transmitted infections (STIs) are very common for any sexually active person. In most cases, they're easily treated and don’t cause complications. However, if left untreated, they can cause long-term complications… including infertility in some cases. So, can chlamydia cause infertility?

Chlamydia is the most common STI in the US and worldwide. Most of the time, it doesn't cause any symptoms, which is why it's dubbed a "silent" infection — research indicates around 70% of people with chlamydia won’t have any symptoms

It's always better to get tested and treated as soon as possible, as untreated chlamydia can lead to severe complications such as chronic pelvic pain, ectopic pregnancy (a pregnancy outside the uterus), and even infertility. Chlamydia and gonorrhea are among the most common causes of infertility. Keep scrolling to learn more about the link between chlamydia and infertility.

What is infertility?

Infertility is when a couple has difficulty getting pregnant naturally after trying to conceive (having unprotected sex) for a year or more. There are two types of infertility: primary and secondary.

  • Primary infertility is when you've never been pregnant and are struggling to conceive. 
  • Secondary infertility is when you've been pregnant before but are now struggling to conceive again. 

We often talk about infertility in the context of female health, but fertility isn't solely a woman's issue. Both men and women can experience fertility challenges, and 40-50% of infertility is attributed to “male factor” infertility

Female infertility is incredibly complex and can be influenced by many different factors, including ovulation disorders, uterine abnormalities, blocked fallopian tubes, and more. Sometimes, there's no identifiable cause for infertility (this is called unexplained infertility).

How does chlamydia cause infertility?

While the bacteria that causes chlamydia (Chlamydia trachomatis) itself doesn't directly cause infertility, if left untreated, the infection can cause complications that may lead to infertility in both men and women.

Untreated chlamydia infections can cause pelvic inflammatory disease (PID) in 10-15% of women, according to the Centers for Disease Control and Prevention (CDC). Women develop PID when certain bacteria, such as Chlamydia trachomatis, travel upwards from the vagina to the upper genital tract, causing permanent damage to the uterus, ovaries, or fallopian tubes. PID can cause serious problems, such as

  • Chronic pelvic pain
  • An increased risk of ectopic pregnancy (where a fertilized egg implants and starts growing outside of the uterus, in the fallopian tube)
  • Difficulties getting pregnant

PID can lead to the formation of scar tissue and blockages in the fallopian tubes (a condition known as hydrosalpinx), which can make it difficult for an egg to be fertilized, thereby increasing the chances of infertility. This is called tubal factor infertility. Scar tissue from PID can also stop a fertilized egg from moving into the uterus, causing an ectopic pregnancy.

While chlamydia infections are easily treatable, the long-term complications of undiagnosed chlamydia are permanent. Of course, not everyone who has chlamydia will develop PID, but the risk does increase. The risk of infertility goes up the longer or more frequently you've had PID.

That's why regular STI testing is so vital for your sexual health. The CDC recommends annual chlamydia screening for all sexually active women — yes, even if you're in a long-term relationship. Pregnant women should also get tested for chlamydia early in pregnancy, and again closer to delivery if appropriate.

Pelvic inflammatory disease symptoms

It can be difficult to tell if you have PID or not. Many people who have it don't experience any symptoms at all. And even if you have symptoms, they might be so mild that you don't notice or mistake them for something else. Some common symptoms of PID include:

  • lower abdominal pain
  • pelvic pain
  • increased and abnormal vaginal discharge that can be green or yellow and has a foul smell
  • bleeding between periods or after sex
  • a high temperature 
  • pain during sexual intercourse
  • painful urination.
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How is pelvic inflammatory disease diagnosed?

Diagnosing pelvic inflammatory disease (PID) can be a bit tricky since there's no single test for it, and there are no "gold standard" diagnostic criteria

To diagnose PID, your doctor will ask you a few questions about your medical and sexual history and then perform a pelvic exam to check for any signs of infection, such as vaginal or cervical tenderness or unusual discharge. They may take swabs from the inside of your vagina and cervix, which will be sent to a lab to check for an active chlamydia infection or other sexually transmitted diseases. 

If the results show a positive test for chlamydia, gonorrhea, Mycoplasma genitalium, or another STD, that might confirm a PID diagnosis. 

The good news is that PID is entirely preventable with early detection and treatment of STIs. So, make sure you get tested regularly and seek medical attention if you experience any symptoms. 

How to treat pelvic inflammatory disease

PID can be treated with a two-week course of broad-spectrum antibiotics that can fight against the bacteria that cause STIs and other vaginal infections.

It's essential to complete the entire course of antibiotics, even if you start feeling better or your symptoms go away. Remember that your sex partner should also be treated to prevent the risk of re-infection, even if they have no symptoms.

If treated promptly, antibiotics can prevent severe damage to your reproductive organs, but they can't reverse any scarring already caused by the infection. And the more you delay treatment for PID, the harder it might be to conceive in the future.

FAQs

What STIs can cause infertility?

Research has shown that chlamydia and gonorrhea are two of the most common causes of infertility. There’s limited data on how other untreated sexually transmitted diseases and vaginal infections affect fertility, but some studies found a possible link between PID and trichomoniasis, Mycoplasma genitalium, and herpes.

Is it hard to get pregnant if you had chlamydia?

Not everyone who gets chlamydia will encounter fertility issues — especially if they treated it early. That said, untreated chlamydia can lead to PID, which can cause infertility. That means fertility treatments like in vitro fertilization (IVF) may be necessary for women who want to become pregnant but are unable to do so due to previous chlamydia infection. IVF can be especially helpful in cases of tubal infertility. IVF is not always successful.

Can chlamydia cause male infertility?

Yes, untreated chlamydia can cause both male and female infertility. Although cisgender men can’t get pelvic inflammatory disease, research shows that untreated chlamydia can cause DNA damage in sperm, which can affect their health and motility (how they move).

How long does untreated chlamydia take to cause infertility?

It's hard to know how long it takes for chlamydia to cause infertility because it varies from person to person. The timing can be anywhere from a few weeks to a few years. However, the risk of infertility goes up the longer or more frequently you've had PID.