Objective: To determine whether interactions between coital frequency, cervical length, and urogenital infection affect obstetric outcomes. Materials and Methods: A total of 268 unselected pregnant women were recruited in the study. The study population consisted of four groups of women: group 1 (n=203) screened negative for bacterial vaginosis (BV) both in the first and second trimesters; group 2 (n=18) screened negative for BV in the first trimester but positive in the second trimester; group 3 (n=33) screened positive for BV in the first trimester but negative in the second trimester; and group 4 (n=14) screened positive for BV both in the first and second trimesters. Urine culture, cervico-vaginal cultures, and bacterial vaginosis were screened between 11-14 weeks and 20-24 weeks. Results: Two hundred fifty women were eligible for analysis in the study after lost-to-follow up patients were excluded. Previous abortion ≥1 and previous preterm delivery at 24-34 weeks ≥1 were statistically significantly higher in group 2. The number of patients who were diagnosed as having preterm premature rupture of membranes (PPROM) was statistically significantly higher in group 4. Sexual intercourse during the first trimester, cervical length during the second trimester, and history of preterm birth (PTB) were statistically significant risk factors for preterm birth <37 weeks (1.27; (1.12-1.44); 5.33; (1.84-15.41); 6.95; (1.58-30.54), respectively). Conclusion: Presence or treatment of BV did not influence rates of PTB. The probability of PPROM would be higher in patients who are BV positive both in the first and second trimesters.