Preterm Premature Rupture of Fetal Membranes: Cervical Ultrasound and Biological Markers to Diagnose Prematurity (RECHOBIOL)

Preterm premature rupture of membranes (pPROM) is defined as a spontaneous rupture before the start of labor ("premature" rupture) and before 37 weeks of gestation ("preterm"). pPROM concern 2-3% of pregnancies. It is the main cause of prematurity since it is responsible for 24 to 42% of preterm deliveries. The time between PROM and childbirth is named the latency period. Its total duration can vary from a few hours to several weeks. Childbirth occurs within 48 hours of rupture for 18 to 93% of cases, within 7 days for 56 to 96% and within 28 days for 78 to 100%. The earlier PROM occurs during pregnancy, the longer the latency period is. The factors associated with a shorter latency period are: cervical changes during admission for pPROM, a shortened cervix on ultrasound or a threat of premature delivery prior to PROM, the existence of uterine contractions, oligoamnios, and the occurrence of a materno-fetal complication of pPROM. In a pPROM situation, a prolonged latency period improves the neonatal prognosis by increasing the gestational age of birth, gives the possibility of administering the corticosteroid treatment of fetal pulmonary maturation and also allows an in utero transfer in an adapted maternity. Several studies have shown a correlation between the length of the cervix during rupture and the latency period in the context of pPROM. To date, there are no effective biomarkers used in current practice to predict this latency period. We want to assess the diagnostic performance of different vaginal (PIBF / PP14 / IGFBP1 native and total) and serum (PIBF / MIF) markers as well as the ultrasound length of the cervix to predict the duration of this latency period in order to better anticipate the risk of prematurity.