Background Adolescents are at high risk for sexually transmitted infections (STIs) because of their high risk behaviour and physiological susceptibility. The present study aimed to find out prevalence of high risk factors and their association with STIs among asymptomatic pregnant adolescents.

Methods This was a cohort study conducted in the Department of Obstetrics and Gynaecology, Vardhman Medical College and Safdarjung hospital in association with Dr B. R. Ambedkar Centre for Biomedical Research, University of Delhi. A total of 320 asymptomatic adolescent pregnant women willing to participate in the study protocol were enrolled. A detailed history including sexual, marital, obstetric, personal and clinical details was taken. After clinical examination, cervical and high vaginal swabs were collected for testing by PCR technique for Chlamydia Trachomatis, Neisseria Gonorrhoea and Trichomonas Vaginalis infections. The data hence collected was analysed to find out prevalence of high risk factors and their association with STIs.

Results Out of 320 women enrolled in the study, 41 (12.81%) tested positive for one of the 3 STIs tested. Most of the subjects were 19 years old (76.56%), belonged to urban area (80.94%), were from low income group (82.81%), had not been to high school (70%) and 78.13% had at least one high risk factor for STIs. Among the high risk factors for STIs studied, 31.87% had age <18 years at the time of first sexual intercourse, 75.94% had never used any contraception, 1.87% had history of tobacco or alcohol use, 7.81% had past history of vaginal discharge. Out of these high risk factors for STIs only past history of vaginal discharge was significantly associated with presence of STIs, p = 0.0001.

Conclusion The high risk factors for STIs are present in more than 3/4^th of pregnant adolescent women and past history of vaginal discharge is significantly associated with STIs.