Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(7):463-468
DOI 10.1590/S0100-72032002000700006
Purpose: to evaluate, in the first and second trimesters of pregnancy, the correlation between cervical length and spontaneous preterm delivery. Methods: cervical length was evaluated in 641 pregnant women between 11-16 weeks' and 23-24 weeks' gestation. Cervical assessment was performed by a transvaginal scan with the patient with empty bladder in a gynecological position. Cervical length was measured from the internal to the external os. The gestational age at delivery was correlated with the length of the cervix. To compare the means in groups of pregnant women who had a term or preterm delivery, we used Student's t test. Sensitivity, specificity, false-positive and false-negative rates, and accuracy were calculated for cervical length of 20 mm or less, 25 mm or less and 30 mm or less in the prediction of preterm delivery. Results: the measurement of cervical length, between 11 and 16 weeks of pregnancy, did not show any statistically significant difference on comparing women who had preterm and term delivery (40.6 mm and 42.7 mm, respectively, p=0.2459). However, the difference between the two groups at 23 to 24 weeks was significant (37.3 mm in the group who delivered prematurely and 26.7 mm in the term group, p=0.0001, Student's t test). Conclusion: there was no significant difference in cervical length, at 11 to 16 weeks, between pregnant women who had a preterm and term delivery. However, at 23 to 24 weeks, cervical length was significantly different between the two groups, and this measurement might be used as a predictor for prematurity.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(6):377-381
DOI 10.1590/S0100-72032002000600004
Purpose: to establish a reference range for cervical length measurement throughout gestation in twin pregnancies and to correlate cervical length with gestational age at delivery. Methods: retrospective analysis of prospectively collected data between 1994 and 2000, involving 149 twin pregnancies undergoing transvaginal ultrasound examination every four weeks for measurement of cervical length. Results: one hundred and twenty-seven women (85.2%) delivered after 34 weeks, 20 (13.4%) between 24 and 33 weeks and two pregnancies resulted in fetal loss before 24 weeks. The mean gestational age at delivery was 36.3 weeks. A total of 497 ultrasound examinations with cervical length measurement were performed in 127 patients with twin pregnancies who delivered after 34 weeks (mean = 4 examinations per patient). All scans were carried out between 9 and 39 weeks (mean = 29.4 weeks). There was an inverse correlation between cervical length measurement and gestational age at the scan in twin pregnancies (r=-0.44; p < 0.0001). The mean value was 44 mm at 10 weeks and 28 mm at 36 weeks. The corresponding fifth percentile values of these gestations were 28 mm and 12 mm, respectively. Cervical length measurement changes were more pronounced in the second half of the pregnancy (Kruskal-Wallis test, p=0.0006). Mean cervical length measurement and 90% prediction interval values were established throughout gestation by regression analysis. Twenty-six cases delivered before 34 weeks, nine of these cases (34.6%) had at least one cervical length measurement below the 5th percentile. Conclusions: cervical length shortens gradually throughout gestation in twin pregnancies but changes are more significant in the second half of the pregnancy. Approximately one-third of the pregnancies that delivered before 34 weeks had at least one cervical length measurement below the 5th percentile for the gestational age.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(5):301-306
DOI 10.1590/S0100-72032002000500003
Purpose: to compare the outcome of pregnancies with and without threatened abortion presenting alive embryo/fetus between 6 and 13 weeks at sonographic evaluation. Method: this was a retrospective case-control study, carried out from February 1998 to December 1999. Criteria for inclusion were: topic and single pregnancy; embryo/fetus cardiac activity present in the ultrasound scan; gestational age between 6 weeks and 13 weeks and 6 days, absence of fetal anomalies, absence of attempt of abortion by drugs or manipulation, absence of maternal disease, known pregnancy result. A total of 1531 pregnancies were examined, of which 258 with threatened abortion (case group) and 1273 without threatened abortion (control group). The two groups were compared regarding outcome such as: abortion, stillbirth, prematurity and intrauterine growth restriction. Results: the percentage of abortion (11,7%) and prematurity (17,8%) were higher in the group with threatened abortion (p<0.001 and p=0.026, respectively). The frequency of stillbirth and intrauterine growth restriction did not differ significantly between the groups.Conclusion: threatened abortion with alive embryo/fetus in 6- to 13- week gestation presented a higher abortion risk and subsequent prematurity.