Chlamydial Infection


The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What is a chlamydial infection during pregnancy?

A chlamydial infection is an infection with any of three species of the Chlamydiaceae family of bacteria that cause disease in humans, particularly the species Chlamydia trachomatis in which case the infection often is called a trachoma. Chlamydial bacteria cause sexually transmitted infections (STIs) in adults, including pregnant women, and also respiratory (lung) and eye infections in adults and newborns.

How common is a chlamydial infection during pregnancy?

A chlamydial infection is the most common bacterial STI in the world, including in women ages 1549 years.  Prevalence of C. trachomatis numbers in the hundreds of millions. The prevalence varies between different regions, but the infection is thought to affect pregnant women with rates similar to those of non-pregnant women. Rates of infection are particularly high in sub-Saharan Africa and parts of Asia. You are at a higher risk of carrying Chlamydia if you are positive for human immunodeficiency virus (HIV), the virus that causes AIDS.

How is a chlamydial infection during pregnancy diagnosed?

Initial clues come from your symptoms, which can include pain with urination and with sexual intercourse, painful menstruation, bleeding between your menstrual periods, vaginal itching or burning, tummy pain, and fever. Symptoms also often include redness and swelling of the conjunctiva of the eyes in childhood, eventually resulting in chronic inflammation and a variable degree of scarring. This is often in connection with whats called trichiasis, the inward turning of the eyelashes such that they irritate the conjunctiva. There are laboratory tests for the organisms. Still, often, the diagnosis is clinical, meaning that your doctor figures it out based on your symptoms, history, and the setting that makes it likely that you suffered a chlamydial infection.

Does a chlamydial infection cause problems during pregnancy?

First of all, prior to pregnancy, inflammation in and around the pelvis (pelvic inflammatory disease [PID]) that often develops in sexually transmitted chlamydial infection can scar your fallopian tubes through which ova (eggs) need to pass for you to become pregnant. In addition to causing infertility, this scarring can slow down the movement of an ovum that becomes fertilized, leading to an ectopic pregnancy, particularly a tubal pregnancy. This means that, rather than implanting in the endometrium of the uterus, the blastocyst resulting from the fertilization, implants in the wall of the fallopian tube. As it grows, this leads to an emergency that threatens the mothers life. If an infection develops when you already are pregnant, you can develop severe pelvic pain and fever. You also have an elevated risk of premature rupture of membranes (water breaking), leading to preterm labor and preterm birth.

Does a chlamydial infection cause problems for the baby?

In addition to the risk of being born preterm, the baby is at risk of severe eye and lung problems, particularly pneumonia.

What to consider about taking medications when you are pregnant or breastfeeding:

  • The risks to yourself and your baby if you do not treat the chlamydial infection
  • The risks and benefits of each medication you use when you are pregnant
  • The risks and benefits of each medication you use when you are breastfeeding

What should I know about using medication to treat a chlamydial infection during pregnancy?

Treatment with antibiotic medications is vital, and there are antibiotic regimens that are considered safe in pregnancy. Erythromycin is the first-line antibiotic for pregnant women with chlamydial infection, but pregnant women also can be treated with amoxicillin.

Who should NOT stop taking medication for a chlamydial infection during pregnancy?

It is very important NOT to stop taking antibiotics without consulting with your physician. If you have a reaction to a particular antibiotic, a different antibiotic can be substituted, but you need to be on the same page as your doctor with this.

What should I know about choosing a medication for my chlamydial infection during pregnancy?

It is important to stay in communication with your health care provider as the release of new studies over time can change the outlook on the role of specific medications during pregnancy.

You may find Pregistrys expert reports about the medications to treat this condition here. Additional information can also be found in the sources listed below.

What should I know about taking a medication for my chlamydial infection when I am breastfeeding?

The antibiotics erythromycin and amoxicillin both are considered safe in lactating women.

What alternative therapies besides medications can I use to treat my chlamydial infection during pregnancy?

There is no alternative to antibiotic treatment for chlamydial infection once you have it. However, all pregnant women and women trying to become pregnant should be screened for Chlamydia.

What can I do for myself and my baby when I have a chlamydial infection during pregnancy?

It is very important to follow the instructions of your physician.

Resources for chlamydial infection in pregnancy:

For more information about chlamydia infection during and after pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations:


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General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.

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