RESUMO
OBJECTIVES: The objectives of this study were to clinically characterize and seek risk factors for the patients with persistently detected alfa-fetoprotein (AFP) in the vagina without showing overt preterm premature rupture of the membranes (PROM). STUDY DESIGN: The cohort study was undertaken using vaginal-cervical specimens collected consecutively between 21 and 40 weeks of gestation from 25 consenting women. Demographic, obstetric, neonatal, and laboratory data from patients with persistent positive results of AFP kit tests without showing overt leakage of amniotic fluid were compared to those from controls. Cervical levels of interleukin-1 alpha, interleukin-1 beta, interleukin-6, interleukin-8, and granulocyte elastase were measured by immunoassay, and the uterine cervix was assessed by transvaginal ultrasonography. Statistical analysis involved Fisher's exact test and Mann-Whitney U test. RESULTS: The incidence of overt preterm PROM was significantly higher in the patients with persistently detected AFP in preterm (3 in 4 cases) than in controls (3 in 21 controls). At sampling before determination of persistently detected AFP, patients with persistently detected AFP had significantly higher cervical levels of interleukin-6 and significantly shorter cervical length than controls. CONCLUSIONS: Patients with persistently detected AFP in the vagina without showing overt preterm PROM have the risk of overt preterm PROM. Increased levels of interleukin-6 in cervical specimens and short cervical length may be risk factors for the occurrence of persistent detection of AFP in the preterm.
