In newborns, untreated chlamydia can cause pre-term delivery, ophthalmia neonatorum (conjunctivitis) and pneumonia. Studies show that chlamydial conjunctivitis and pneumonia occur in 18-44% and 3-16% of infants born to those with chlamydia.
The best way to avoid complications is by screening and treating chlamydia in pregnant individuals. To do this, all pregnant people under age 25 should be screened at the first prenatal visit and during the third trimester, as well as those 25 and older who have a new or more than one sex partner. After treatment, retesting should be done four weeks and three months later.