Diagnostic ultrasound criteria was the display of an image of bright two or three parallel lines arranged in successive segments, circling the fetal10 neck. Used ultrasound equipment brand Medison Sonoet, model 5000, 3.5 MHz, with biconvex transducer electronic and thermal paper printer camera brand Sony. The standard of comparison was direct viewing of the presence or absence of circular cord during vaginal delivery or cesarean section. Statistical analysis to evaluate discordance between the use and the gold standard was the test of McNemar square Xi. Center for Environmental Health understood the implications. For the evaluation of the association between circular cord and scores of Apgar score at birth, exact test of Fisher, as well as to evaluate the association with pregnancy resolution via are used. For the evaluation of the diagnostic test was carried out calculations of sensitivity and specificity, with their confidence intervals of 95%, in addition to the positive and negative predictive values, as well as test accuracy and likelihood ratio. A P value of equal to or less than 0.05 was considered significant.

RESULTS General characteristics of the 57 patients studied were the following: the average age of the patients was 25.5 years, 36.8% of patients was primigesta (n = 21), 17.5% secundigesta (n = 10), 46.6% had three or more pregnancies (n = 26). All patients were enrolled at term, in effective labor and uncomplicated, placenta Placentae, membranes intact. The resolution of the birth was vaginal in 80% of patients (n = 47) and by caesarean section in 20% (n = 10). The cesarean section indication was fetal distress acute in 50% of cases (n = 5), cephalopelvic disproportion in 30% (n = 3), and the remaining 20%, one was by prolonged second stage and another by dystocia of contraction. Of the babies born by vaginal delivery, 7 had circular lace, and of those born by caesarean section, 10 had circular cord. The analysis with Fisher’s exact test showed a statistically significant association between circular cord and cesarean section (p = 0, 000468). The General characteristics of the RN were 3,350 more or less 0,245 kg weight, 63 male and 51 female. The proportion of RN with Apgar score > 8 was 91.

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.