Abdoulreza Esteghamati - Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran
Ali Mazouri - Shahid Akbarabadi Clinical Research Development Unit, Iran University of Medical Sciences, Tehran, Iran
Mehri Alipour - Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran
Morteza Haghighi Hasanabad - Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran

Introduction and Objectives: Chlamydia trachomatis (C. trachomatis) is leading bacterial cause of sexually transmitted infections (STIs) in men and women, worldwide. Pregnant women can transmit this microorganism vertically to their newborns and cause conjunctivitis secondary to STIs. While there no program for screening of STIs among Iranian pregnant women, limited data are existed on the vertical transmission rate of C. trachomatis from our country. To address this gap, we aimed the current study to evaluate the frequency of C. trachomatis infection in a sample of pregnant women before vaginal delivery and then, to assess the rate of vertical transmission for this microorganism from genital tract of infected mothers to the eyes of their newborns. Materials and Methods: Endocervical and conjunctival swabs were collected from pregnant women and their newborns before and after vaginal delivery, respectively. DNA was extracted from specimens and tested by an in-house PCR assay to amplify a 241bp fragment of C. trachomatis. Result: Chlamydia trachomatis was detected in 9.6% (11 of 125) and 1.6% (2 of 125) of pregnant women and newborns, respectively. Both infected infants were born from asymptomatic infected women. The vertical transmission rate of C. trachomatis in this study was calculated as 18.1% (2 of 9). Additionally, our results revealed that presence of C. trachomatis in the eyes of newborns after birth is significantly in relation with genital C. trachomatis infection in their mothers (OR= 0.16, 95% CI= 0.03-0.7, P= 0.002). Conclusion: Pregnant women with asymptomatic infection of C. trachomatis have a key role in the distribution of chlamydial conjunctivitis in newborns. Since ocular prophylaxis in neonates is not effective for chlamydial conjunctivitis, therefore, education and screening of pregnant women, as well as treatment of infected cases, remain as the best approach for controlling the disease.

Chlamydia trachomatis, Pregnant Women, Vertical Transmission, Newborns