Artifacts interfering with sonographic imaging of the uterine cervix in pregnancy are described. Increasing the amount of fluid in the urinary bladder closes the cervix and alters the configuration of the lower uterine segment, while increased intra-uterine pressure results in reciprocal changes. Angulation of the transducer and manual pressure thereon distort sonographic findings. It is concluded that, contrary to recent reports in the literature, sonography cannot reliably demonstrate changes in cervical compliance during pregnancy. Vaginal examination remains the ultimate diagnostic modality for the diagnosis of the incompetent cervix, while sonography may be used as an adjunct only.
PMID 3541483 3541483 DOI 10.3109/00016348609158394 10.3109/00016348609158394 Confino et al. 1986, Confino 1986
Cite this article
Confino, E., Mayden, K. L., Giglia, R. V., Vermesh, M., & Gleicher, N. (1986). Pitfalls in sonographic imaging of the incompetent uterine cervix. Acta obstetricia et gynecologica Scandinavica, 65(6), 593-597. https://doi.org/10.3109/00016348609158394
Confino E, Mayden KL, Giglia RV, Vermesh M, Gleicher N. Pitfalls in sonographic imaging of the incompetent uterine cervix. Acta Obstet Gynecol Scand. 1986;65(6):593-597. doi:10.3109/00016348609158394
Confino, E., et al. "Pitfalls in sonographic imaging of the incompetent uterine cervix." Acta obstetricia et gynecologica Scandinavica, vol. 65, no. 6, 1986, pp. 593-597.
Our purpose was to determine whether perioperative transvaginal ultrasonographic evaluation of the incompetent cervix treated with emergency cerclage is predictive of pregnancy outcome. Twenty-nine women who underwent emergency cerclage at 16 to 26 weeks of gestation had transvaginal ultrasonographic evaluation of the cervix within 48 hours before and after surgery and at least three times thereafter until 28 weeks of gestation. The following measurements were obtained: (1) funnel width, (2) funnel length, (3) endocervical canal length, (4) the distance between the internal and external os, (5) upper cervix (length of closed endocervical canal above the cervical cerclage), (6) lower cervix (endocervical canal length below suture), and (7) cervical index (1+ Funnel length/Endocervical canal length). Values are reported as the median in millimeters, and statistical analysis was performed by use of the Mann-Whitney U test, Wilcoxon signed-rank test, Spearman rank correlation, 2 x 2 contingency tables, and multiple regression analysis with significance set at p < 0.05. Cerclage procedures resulted in significant improvement in postoperative median measurements of funnel width (15 vs 4.0 mm, p < 0.0001), funnel length (29 vs 3 mm, p < 0.0001), and endocervical canal length (2 vs 27 mm, p < 0.0001). There was a significant relationship between gestational age at delivery and the following preoperative funnel width (r = -0.51, p = 0.007), postoperative endocervical canal length (r = 0.39, p = 0.04), length of the lower cervix (r = 0.39, p = 0.038), and the cervical index (r = -0.39, p = 0.038). An upper cervical length < 10 mm was a good predictor of delivery before 36 weeks of gestation, sensitivity 85.7% (12/14), specificity 66.7% (10/15), positive predictive value 70.6% (12/17), negative predictive value 83% (10/12), and Fisher's exact p = 0.008. Postoperatively all patients had upper cervical lengths < 10 mm by 28 weeks of gestation. Preoperative digital assessments of cervical dilatation before surgery did not correlate with gestational age at birth (r = -0.031, p = 0.36). In cases of cervical incompetence treated with emergency cerclage, perioperative transvaginal ultrasonographic assessment of the cervix reveals that the procedure results in improved ultrasonographic status of the cervix and that the ultrasonographic cervical findings before and after surgery correlate with pregnancy outcome.
There are no absolute objective diagnostic criteria for cervical incompetence. Abdominal and endovaginal ultrasonographic assessment of endocervical length, both of which have been associated with technical problems, have been used to establish the diagnosis. Cervical cerclage may be useful in preventing silent cervical dilatation; however, no prospective trials with and without cerclage have been performed when endocervical shortening has been demonstrated by ultrasonography.
To evaluate the feasibility of the use of serial ultrasound measurements of cervical length, membrane protrusion, and dilatation to discriminate between the competent and the incompetent cervix, 107 at-risk patients and 30 control subjects were examined prospectively. Patients were divided into five groups based on treatment and method of diagnosis. Epidemiologic, ultrasound, and outcome data were analyzed. Means and standard deviations for ultrasound measurements were established. Highly significant differences between all prediagnostic and postdiagnostic-pretreatment measurements were found (p less than 0.001). Highly significant differences were also found between all postdiagnostic-pretreatment and postdiagnostic-posttreatment measurements (p less than 0.001). No significant differences between prediagnostic and postdiagnostic-posttreatment measurements were noted. The incidence of preterm delivery was significantly higher among untreated diagnosed patients (p less than 0.01). By combined clinical and ultrasound criteria 51 patients (47.7%) were identified as not having cervical incompetency. Fifty-six patients (52.3%) were diagnosed.
Koivunen R et al., 1999·Acta Obstet Gynecol Scand·
To study the prevalence of polycystic ovaries (PCO) in women of reproductive age. A total of 189 healthy volunteers aged 20-45 years were examined. The subjects were divided into two groups according to age: < or =35 and > or =36 years. Transvaginal ultrasonography was performed and blood samples were collected on cycle day 1-6. The prevalence of PCO in the entire study population was 14.2% (27/189). In the age group of < or =35 years the prevalence was 21.6% (19/88) and in the age group of > or =36 years 7.8% (8/101). Compared to women with normal ovaries, those with PCO had significantly higher serum testosterone (T) concentrations. Women with PCO tended to have lower serum FSH concentrations and higher LH/FSH ratios than controls. Women with PCO had significantly more irregular cycles (44% vs. 19%, p=0.001) and problems in conceiving (25.9% vs. 9.2%, p=0.01) than women with normal ovaries. The findings demonstrate that the prevalence of PCO in healthy women varies with age, being more common among women aged < or =35 years than in those aged > or =36 years. Although the hormonal parameters and clinical findings among women with PCO mimicked those of PCOS, it remains unclear if these women will later develop full-blown syndrome.