 The principal objective is to use a cost-effectiveness study to assess the medical and economic impact of a new strategy for the screening and subsequent treatment of vaginal flora anomalies before the 20th week of gestation- molecular biology techniques PCR for A. vaginae and G. vaginalis by point-of-care testing will test self-collected vaginal samples in a population of pregnant women at low risk of preterm delivery. There are multiple secondary objectives, including assessment of the effect of the strategy on the following indicators- delivery before 26, 32, and 37 weeks. Methods-An open-label prospective randomized study will compare 2 groups with different management of their pregnancies. Pregnant women at low risk, regardless of any symptoms, will be randomized into 2 groups. The study will not include women at high risk of preterm delivery. Innovative strategy group A- these women will undergo routine screening for bacterial vaginosis by analysis of their self-collected vaginal samples with this innovative technique. 