How Do STIs Affect Fertility?

Many women who are trying to conceive are prepared to chart their cycle, take a prenatal vitamin, and clean up their diet, but what about the effect of sexually transmitted infections (STIs) on fertility? Some of the most common STIs can have a profound effect on getting pregnant and in some cases require treatment before conception can occur. But not to worry, I'm going to break it all down for you.


Chlamydia, Gonorrhea & PID

Chlamydia and gonorrhea are both bacterial infections that are sexually transmitted. They are caused by different bacteria and have different sets of symptoms, but both can usually be easily treated with a round of antibiotics. The problem for fertility comes if and when they go untreated, often because they don't cause symptoms or only mild symptoms, and eventually they may lead to a condition caused Pelvic Inflammatory Disease (PID.)

PID is an inflammatory condition of the reproductive organs that is most often caused by chlamydia or gonorrhea. Rarely it may be caused by a non-sexually transmitted infection in the uterus, for example, douching can increase the risk of PID by moving naturally occurring bacterial from the vagina up into the uterus. If PID is active while trying to conceive, the infection can inflame the uterine lining, where implantation takes place, and it may even channge the pH of the uterus and make it inhospitable for sperm or a developing embryo.

The inflammation that PID causes may eventually lead to scarring, especially in the fallopian tubes, which can have a huge effect on fertility, as the fallopian tubes are the only route for sperm to meet the egg and for a fertilized egg/embryo to travel back into the uterus. If one or both tubes are blocked, then everything else (egg quality, sperm quality, uterine lining, etc.) can be in good working order, but fertilization may not be able to occur.

Diagnosis & Treatment 

Both chlamydia and gonorrhea can be tested via a swab of the cervix, which can be paired with a standard Pap smear, and both infections are often treated with antibiotics. If there's a chance that infection was longstanding and that PID has effected the fallopian tubes, then a hydrosalpingogram (HSG) may be needed, which is a test that involves filling the uterus with fluid to visualize if the tubes are open. Consult your gynecologist or OBGYN if you think you'd like to be tested for infection, or if you think you need an HSG.

If just one tube is blocked, no treatment may be needed. Believe it or not our fallopian tubes are able to reach over and grab an egg from the opposite ovary during ovulation. But if both tubes are blocked, then surgery or In Vitro Fertilization (IVF) may be needed, as IVF can bypass the tubes entirely. Consult a reproductive endocrinologist, or ask your OBGYN for a referral to one, if your HSG showed both of your fallopian tubes to be blocked.



Human Papillomavirus (HPV) is a very common STI, it's estimated that 45% of men and 40% of women have it. It often causes no symptoms at all, especially in men, who rarely know they are carriers, and it may even resolve on its own. HPV itself does not cause infertility, but may result in secondary conditions which can.

One of the most concerning risks of HPV is irregular cell growth of the cervix and cervical cancer. Let's start with irregular cell growth, which is very common and usually treated with a simple procedure to remove the irregular cells. If this procedure is done shortly before conceiving, it may cause issues with cervical competency (it's ability to stay closed during pregnancy.) But it may not have any effect on conception or pregnancy, It really depends on how much of the cervix needed to be removed and how much recovery time there was. 

Obviously, if irregular cells on the cervix have progressed to cancer, that can affect the immune system and inflammation levels, as well as make pregnancy much more risky. If a cancer diagnosis has been confirmed, often women are put on birth control to prevent pregnancy until treatment is complete.

Cancer treatment, however, can have a huge effect on fertility because aggressive treatments, such as chemotherapy, might have a detrimental effect on egg quality. I've had a few patients with early stage cancer undergo egg retrieval (part of the IVF process) prior to undergoing chemotherapy in hopes of preserving some of their eggs, but that wholly depends on diagnosis and treatment plan, as determined by you oncologist (cancer doctor) and reproductive endocrinologist (fertility doctor.)

Diagnosis & Treatment 

While HPV itself is not typically screened for as part of a Pap smear (it can be if you ask,) irregular cell growth is tested for. Keep in mind, just because you have HPV doesn't mean you'll necessarily develop irregular cell growth, or that the irregular cell growth will eventually turn to cervical cancer. Regular screenings via Paps is how we keep an eye on cervix health and prevent these from developing into something dangerous.

The standard recommendation is to get a Pap smear starting at age 21 every 3 years, as long as you've never had an abnormal result before. If you do get an abnormal result, it doesn't necessarily mean you have cervical cancer, but your doctor may recommend a follow up Pap smear, or a procedure to remove the irregular cells, and they may recommend you get Paps more frequently than every 3 years. Consult your doctor for screening and treatment options.




Another viral infection, herpes is incredibly common, especially in women who experience it in rates as high as 20%. The effect of herpes on fertility in women is unclear, though it has been linked to lower sperm counts in men.

Diagnosis & Treatment

Herpes can be tested via a blood test, and antiviral medications may be used to treat an active infection or prevent flare-ups, but in many cases medication may not be needed as the virus is dormant in some people's systems. Consult your doctor for testing and treatment options.



We hear much less about syphilis, compared to other STIs, but it's still out there. In fact, it's been on the rise the past 10 years. Syphilis is another sexually transmitted bacterial infection, usually transmitted when there's an open sore on the mouth or genitals. Usually within 3 weeks it causes a sore to appear in the infected individual, and if untreated it may eventually lead to a skin rash and neurological symptoms. Syphilis can also contribute to miscarriage or stillbirth if pregnancy occurs while the infection is active.

Diagnosis & Treatment 

A blood test can test for the presence of syphilis, and antibiotics can treat the infection, though they aren't able to reverse more advanced signs of neurological damage. Consult your doctor for testing and treatment options.



Human Immunodeficiency Virus (HIV) can be life threatening if it progresses unmanaged, as it suppresses our own immune system, which is our defense mechanism against simple colds, flus, and infections. When HIV is active in the body it can cause PID (see above for more on its affect on fertility) and it can be quite contagious via unprotected sex, which can make trying to conceive naturally quite risky if one partner isn't HIV positive. Obviously, the risk of transmission from mother to child is also a concern to be taken into account when making a plan for conception.

Diagnosis & Treatment 

HIV can be tested for via blood, saliva, or urine. and while there's not yet a "cure," anti-retroviral medications are extremely effective at slowing it's progression, improving the patient's quality of life, and reducing how contagious it is. In fact, if conception is achieved via IVF, the risk of transmission between partners and from mother to child can be very low. Consult a reproductive endocrinologist (fertility doctor) to learn more about your treatment options and how to reduce risk of transmission.


Want to learn more?

I discuss STIs and fertility along with a ton of other topics in Foundations of Fertility - my 6-week masterclass in all things fertility. In fact, we cover hormones and common hormonal imbalances, diet, supplements, herbs, Chinese medicine, cycle charting, and how to evaluate your own fertility. If you're serious about trying to conceive this course is for you!