OBJECTIVE: Comparing the diagnostic capacity of the abdominal ultrasound in detection of circular cord. Design: Analytical clinical study. MATERIAL and methods: We studied 57 patients with pregnancy at term and in labor. Prior to his hospitalization, to each patient abdominal obstetric ultrasonography (use), was conducted him to identify the presence or absence of lace circular, which was compared to the findings at the time of childbirth or caesarean section (gold standard). RESULTS: The prevalence of circular cord in full-term pregnancies diagnosed by use was 21.1%. Test sensitivity was 80% (CI 95%, 72.7 to 87.3), 96% (CI 95%, 92.9 to 99.1) specificity and positive and negative predictive values were 87% and 94%, respectively. The accuracy of the test was 92%. The square Xi of McNemar for analysis of the discrepancies between the two tests was not significant (p = 0, 7236).
The reasons for likelihood for positive and negative results were 20 and 0.20, respectively. CONCLUSIONS: The study ultrasound during labor for the diagnosis of circular of lace is highly specific (96%), which allows you to be used as a screening test to identify high risk with lace circular pregnancies. Key words. Ultrasound; Umbilical cord; Circular cord. SUMMARY objective: To compare the diagnostic ability of abdominal ultrasounito detect fetal nuchal cord.
DESIGN: Clinical analytical study. MATERIAL AND METHODS: Fifty-seven term pregnant patients in work had abdominal ultrasound (US) on admission in order to identify fetal nuchal cord and compare such finding with outcome at delivery or cesarean-section (gold standard). RESULTADOS: Nuchal cord prevalence diagnosed by ultrasound was 21.1%, with 80% sensitivity (95% CI 72.7 to 87.3), 96% specificity (95% CI 92.9 to 99.1), and positive and negative predictive values of 87% and 94%, respectively. Test accuracy was 92%. McNemar discordance analysis between obstetric US s and gold standard was not significant (p = 0, 7236) and the likelihood ratios for positive and negative results were at 20 and 0.20, respectively.