Chlamydia and pregnancy: what you need to know

Chlamydia is the most commonly reported STI in Australia, and left untreated during pregnancy it can affect both you and your baby. The reassuring news is that chlamydia is easy to detect and easy to treat, so with the right care you can protect your own health and your baby’s.

What is chlamydia?

Chlamydia is an STI spread through sexual activity, including skin-to-skin contact during vaginal, anal and oral sex, as well as sharing sex toys or genital-to-genital contact. Importantly, it can also be passed to a baby during birth if the mother is infected.

Most people with chlamydia don’t know they have it, because it usually causes no symptoms. But untreated infection can lead to long-term complications, and it can pose a real risk to a pregnancy and to a newborn who catches it during birth.

Risks of chlamydia during pregnancy

If chlamydia isn’t treated, it can affect the reproductive organs and raise the risk of several serious pregnancy complications.

Preterm delivery

One of the most significant risks is preterm delivery, where a baby is born before 37 weeks. Research suggests chlamydia can increase the risk of very early preterm delivery (before 32 weeks) by around four to five times compared with pregnancies without the infection.

Premature rupture of membranes

Untreated chlamydia is linked to the amniotic sac rupturing before labour begins, which raises the risk of infection, umbilical-cord problems, and difficulties during delivery.

Infection of the fluid around the baby

Chorioamnionitis, an infection of the membranes and fluid surrounding the baby, can develop and poses risks to both mother and baby. Early delivery is sometimes recommended if it occurs.

Low birth weight

Untreated chlamydia has been associated with growth restriction in the uterus, meaning a baby may not grow as well as expected and may have a low birth weight, which can increase the chance of needing specialised care after birth.

Newborn eye infections

If chlamydia is passed to a baby during birth, they can develop an eye infection (conjunctivitis), which can lead to serious complications including blindness if not treated promptly. Up to 40% of newborns with chlamydia develop conjunctivitis.

Pneumonia in newborns

Babies who catch chlamydia from their mother can also develop pneumonia, which may cause ongoing lung problems if untreated. This occurs in around 10% to 20% of cases.

Risks for future pregnancies

Even if you and your baby seem unaffected at the time, untreated chlamydia can cause problems later. It can lead to pelvic inflammatory disease (PID), where the infection spreads to the reproductive organs, raising the risk of ectopic pregnancy and infertility down the track.

Testing for chlamydia in pregnancy

The only way to know if you have chlamydia is an STI test. Because of the risks in pregnancy, testing is recommended for everyone trying to conceive, so any infection can be treated beforehand. Pregnant women under 30 should also be tested at their first antenatal visit, and women of any age should be screened if they have risk factors, such as:

• a new sexual partner
• multiple sexual partners
• a partner who has other partners
• a partner with a known or suspected STI.

Treating chlamydia during pregnancy

Chlamydia is easily treated with antibiotics, and treatment is recommended during pregnancy. A clinician will prescribe a course suitable for pregnancy. You’ll need to avoid all sexual contact for 7 days after starting treatment (or until the course is finished and any symptoms have gone, whichever is later) to avoid passing it on, and a follow-up test around 3 months later confirms the infection has cleared.

Treating babies with chlamydia

Preventing infection through screening and treatment during pregnancy is always preferable, but there are effective treatments for newborns who do catch chlamydia, and starting early is important. Conjunctivitis and pneumonia are both treated with a course of antibiotics; a baby with conjunctivitis may also be seen by an eye specialist, and a baby with pneumonia may need chest imaging to confirm it has resolved.

Protect you and your baby’s health

Chlamydia in pregnancy is very manageable when it’s found and treated early. The key is regular screening, and prompt antibiotic treatment if you test positive, which helps prevent complications during pregnancy and after your baby arrives. Testing is quick, easy and discreet.