engleski

Screening for preterm delivery and evidence to support the intervention

Preterm delivery remains one of the most intractable problems that contribute to perinatal morbidity and mortality in obstetric practice in developed countries. The prevalence of preterm delivery varies from 6% to 15% of all deliveries. It results from a series of disorders, implicating maternal and fetal disease, some of which are explained and inter-related, and others of which are of unknown cause. Epidemiological risk factors, of which parental socioeconomic status is among the most important, have a huge bearing on incidence and outcome of preterm birth. Research efforts to address this problem have risen substantially over the past 10 years, but have not resulted in improvements in prediction and prevention of preterm delivery. About 75% of perinatal deaths occur in infants born prematurely, with over two thirds of these arising in the 30– 40% of preterm infants who are delivered before 32 weeks' gestation. Despite new and aggressive prophylactic, diagnostic and therapeutical treatments the incidence of preterm birth remains unchanged in the last few decades. Current methods of identifying pregnant women at risk of preterm delivery mostly rely on positive obstetric history, suggestive symptoms and signs (abdominal or pelvic cramps and/or pressure, low dull backache, increase or change in vaginal discharge and uterine contractions) and evaluation of the cervix by digital examination. All of these methods have low sensitivity, specificity and positive predictive value. As a consequence of the false clinical assessment of premature delivery risk, some pregnant women may be unnecessarily monitored, hospitalized and receive tocolytic agents that may be dangerous for both, the mother and the fetus. On the other hand, some pregnant women at high risk of preterm delivery may have a late institution of corticosteroid prophylaxis and tocolytic therapy. Transvaginal cervical sonography (TVCS) of the uterine cervix has been suggested as a method for the quantitative and qualitative cervical evaluation and thus establishes the objective risk for preterm delivery. It is particularly useful in the detection of women with cervical insufficiency and this group is of special interest as there is a potential intervention in the form of cervical cerclage. The advantage of TVCS over the digital examination (DE) is related to the facts that the supravaginal portion and internal cervical axis are extremely difficult to evaluate digitally. TVCS also allows quantitative and qualitative measurement of the cervix reducing the inter and intra-observer variations. In several reports TVCS was found to be useful in the screening process for women at risk for preterm delivery in high risk population. However, even in a low risk population it was found to of the same diagnostic accuracy compared to widely used clinical examination. There is a still open question about benefits of cervical stitch – cerclage in the group of women with so called cervical insufficiency. In this presentation we will try to summarize the recent knowledge about the named subjects.

pre term delivery; screening; diagnosis; treatment

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