Prediction of preterm delivery by endovaginal ultrasonography: review article

Preterm delivery is the leading cause of neonatal mortality. Thus predictin g a preterm delivery is a major obstetrical problem. Endovaginal ultrasonog raphy is a highly reliable and reproducible method of cervical examination. Unlike with a digital cervical examination the entire length of the endoce rvical canal can be measured. Using this tool, measuring the dilatation of the internal os does not require the examining finger to be placed inside t he endocervical canal. Therefore, the infernal os can be measured even if t he external os is closed. While a digital examination assesses the " dilata bility ", of the internal os, an ultrasonography assesses the " true degree of dilatation ". In a low-risk population endovaginal cervical ultrasonogr aphy helps rule out a preterm delivery if cervical length is long enough. I f can also detect cervical incompetence. In a high-risk population, women w hose cervix is longer than 30 millimeters can be identified. These women ha ve over 80 % chance to deliver on or after 36 weeks of pregnancy. Prelimina ry studies suggest that performing an endovaginal ultrasonography could dec rease the number of false positive clinical diagnosis of modified cervix an d thus, save long, expensive and inefficient hospital stays. Prospective ra ndomized, controlled studies are needed to confirm these results.