From the Guidelines
Pregnant women with chlamydia should be treated with antibiotics before delivery to prevent transmission to the newborn, as treatment of infected pregnant women usually prevents transmission of C. trachomatis to infants during birth 1. The recommended treatment is azithromycin 1 gram orally as a single dose, which is safe during pregnancy. If azithromycin cannot be used, alternatives include amoxicillin 500 mg orally three times daily for 7 days or erythromycin base 500 mg orally four times daily for 7 days. Some key points to consider in the management of chlamydia in pregnancy include:
- Treatment should ideally occur at least 7 days before delivery to reduce the risk of transmission.
- If a woman with untreated chlamydia undergoes vaginal delivery, the newborn should receive prophylactic treatment with erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into 4 doses for 14 days.
- The infant should also be monitored for signs of conjunctivitis or pneumonia, which are common manifestations of neonatal chlamydial infection.
- Chlamydia trachomatis is transmitted to approximately 50% of infants born vaginally to infected mothers, making treatment crucial.
- Sexual partners of the infected woman should also be treated to prevent reinfection, and a test of cure should be performed 3-4 weeks after completing treatment to ensure the infection has resolved, as noted in various guidelines including those from 1993 1, 1998 1, and 2002 1.
From the Research
Vaginal Delivery with Chlamydia
- There is limited research directly addressing vaginal delivery with chlamydia, but studies on chlamydia treatment and its effects on the body can provide some insights.
- Azithromycin is a commonly used antibiotic for treating chlamydia, and its effectiveness has been demonstrated in several studies 2, 3.
- A study published in 2025 found that azithromycin treatment can alter the microbial composition and function of the endocervical, vaginal, and rectal microbiomes in women with chlamydia trachomatis infection, potentially leading to resistance mutations and microbiome shifts 4.
- Another study from 2002 investigated the effect of prolonged treatment with azithromycin, clarithromycin, or levofloxacin on Chlamydia pneumoniae in a continuous-infection model, finding that a 30-day treatment reduced but did not eliminate the infection 5.
- While these studies do not directly address vaginal delivery with chlamydia, they suggest that antibiotic treatment can have significant effects on the body's microbial composition and function, which may be relevant to consider in the context of pregnancy and childbirth.
- A 2025 study on multidrug resistance in group B Streptococcus causing urinary tract infection found that erythromycin exposure can have a protective effect against oxidative stress, but this study does not directly relate to chlamydia or vaginal delivery 6.