Preterm birth rate is 7.2% in Quebec, it's risen worldwide in the past decade and it's the leading cause of perinatal mortality and morbidity. Preterm birth is a major public health problem. Preterm labor leading to preterm birth is difficult to diagnose and prediction of preterm birth is a medical challenge. In the past years, research found that transvaginal ultrasound to assess the cervix of the uterus and vaginal detection of inflammatory protein, specific bacteria and fetal fibronectin can help to detect women at increase risk of preterm delivery. The investigators believe that a combination of these tests can lead to a better prediction of preterm delivery. The investigators want to conduct a study among women judged at increase risk of preterm delivery by their physician (having contractions, modified cervix, past-history of preterm delivery or multiple pregnancy) and assess their cervix by ultrasound and sample their vaginal secretion. The investigators want to analyze the vaginal sampling and look for inflammatory proteins. The objective of this study is to prove the feasibility of this assessment method and elaborate a better predictive test that the investigators can easily use in obstetrics clinics and hospitals.

Preterm birth rate in Quebec is 7.2% and, despite extensive research, the rate of preterm birth has risen worldwide over the past decades. Preterm birth is, all over the world, the first cause of perinatal mortality and morbidity. Spontaneous preterm birth (sPTB) groups premature births with intact and ruptured membranes and represents 70% of preterm delivery. The two conditions associated with sPTB share a common physiopathology and a progressive cascade of events. Extensive evidence supports a central role for the production of prostaglandins, inflammatory cytokines and matrix metalloproteinases (MMP) in the cervix and decidua to promote cervical ripening and decidual and fetal membrane activation but, the exact progression of events remains unclear. Several factors were described as risk factor for sPTB like bacterial vaginosis, inflammatory cytokines and fetal fibronectin in vaginal secretions. The transvaginal ultrasound of the cervix (TVUS), which estimates the length and the aspect of the cervix, can be used as predictive factor of preterm birth. To date, no study has addressed the supra-cervical region by transvaginal ultrasound. This region may be an important key of the inflammatory process leading to sPTB. The assessment of this region by ultrasound can be a predictive marker of sPTB. We want to prove the feasibility of this new approach of sPTB prediction : the transvaginal ultrasound assessment of the supracervical and cervical region associated with detection of vaginal inflammation.

Inclusion Criteria:

• Live singleton or multiple pregnancy
• Clinical risk of preterm delivery
• Pregnancy between 20 and 34 gestational weeks

Exclusion Criteria:

• Delivery on the day of the ultrasound
• Major fetal anomaly
• Previa placentation

At risk women referred by their physician to the MFM clinic for evaluation of preterm birth risk.