Pitfalls in sonographic imaging of the incompetent uterine cervix

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.     

Sonographic assessment of the incompetent cervix in pregnancy.

Ultrasonography (US) was done in 40 women with a history of recurrent midtrimester abortion. The results were compared with those of a control group who consisted of 53 women with no previous history of abortion and had had at least one full term pregnancy with normal vaginal delivery. Mean internal cervical os diameters of 16.0 mm and 22.5 mm at 10 and 27 weeks gestation respectively were recorded in the cervical incompetent patients while mean values of 7.7 mm and 14.5 mm at 13 and 28 weeks gestation were observed in the normal control subjects. Full analysis of covariance showed statistically significant difference in the internal os diameter between the control group and the cervical incompetence cases (t90 = 9.33, P less than 0.001).     

Serial colour flow duplex scanning of the veins of the lower limb throughout pregnancy

Objective To examine changes in diameter and reflux in normal veins of the lower limb throughout pregnancy.
Methods Fifty-seven women were recruited into the study and 43 completed the full assessment to six weeks postpartum. Thirteen had pre-existing venous disease and are reported elsewhere. The veins were assessed in both lower limbs using colour flow duplex scanning. This was performed at a 75° tilt measuring vein diameter and the presence or absence of reflux. Measurements were made at 12, 20, 26, 34, 38 weeks of gestation and 6 weeks postpartum.
Results No new reflux developed in any of the veins studied. In the superficial system the maximum change was seen in the long saphenous vein at 34 weeks, on the left side the vein diameter failed to return to baseline size. Significant change also occurred in the superficial femoral vein. Dilatation of the deep veins of the calf was observed being greater in the left posterior tibia1 and the left peroneal at the mid-calf point.
Conclusion Colour flow duplex scanning is an acceptable method of assessing the lower limb veins in pregnancy. Maximum diameter changes were seen in the long saphenous vein and in the deep veins at mid-calf. No new reflux developed during the gestation period in veins which were previously normal.     

Serial colour flow duplex scanning of the veins of the lower limb throughout pregnancy.

OBJECTIVE: To examine changes in diameter and reflux in normal veins of the lower limb throughout pregnancy. METHODS: Fifty-seven women were recruited into the study and 43 completed the full assessment to six weeks postpartum. Thirteen had pre-existing venous disease and are reported elsewhere. The veins were assessed in both lower limbs using colour flow duplex scanning. This was performed at a 75 degree tilt measuring vein diameter and the presence or absence of reflux. Measurements were made at 12, 20, 26, 34, 38 weeks of gestation and 6 weeks postpartum. RESULTS: No new reflux developed in any of the veins studied. In the superficial system the maximum change was seen in the long saphenous vein at 34 weeks, on the left side the vein diameter failed to return to baseline size. Significant change also occurred in the superficial femoral vein. Dilatation of the deep veins of the calf was observed being greater in the left posterior tibial and the left peroneal at the mid-calf point. CONCLUSION: Colour flow duplex scanning is an acceptable method of assessing the lower limb veins in pregnancy. Maximum diameter changes were seen in the long saphenous vein and in the deep veins at mid-calf. No new reflux developed during the gestation period in veins which were previously normal.     

Diagnostic ultrasound in the assessment of patients with incompetent cervix

Twenty-five pregnant women with suspected cervical incompetence were assessed by serial ultrasound. A dilating internal os was documented in one patient, incompetence was ruled out in two, and a 'slipping suture' was demonstrated in another; the remaining patients were subjected to cerclage on the basis of their history alone. Patients in whom the diagnosis of cervical incompetence is indefinite should have a diagnostic ultrasound scan to visualize the cervix for length, opening of the canal and integrity of the internal os. Selective ultrasonography may be beneficial in both the diagnosis and treatment of cervical incompetence.     

Diagnostic ultrasound in the assessment of patients with incompetent cervix

Summary. Twenty-five pregnant women with suspected cervical incompetence were assessed by serial ultrasound. A dilating internal os was documented in one patient, incompetence was ruled out in two, and a ';sliing suture' was demonstrated in another; the remaining patients were subjected to cerclage on the basis of their history alone. Patients in whom the diagnosis of cervical incompetence is indefinite should have a diagnostic ultrasound scan to visualize the cervix for length, opening of the canal and integrity of the internal os. Selective ultrasonography may be beneficial in both the diagnosis and treatment of cervical incompetence.     

Transabdominal cerclage for closure of the incompetent cervix

In addition to the limited published experience with transabdominal cervical cerclage (TCC) we report the use of this procedure in 14 women with a diagnosis of cervical incompetence, and a cervical deformity or defect precluding the usual transvaginal approach. In 13 pregnant patients and in one nonpregnant woman a band was placed transabdominally around the cervix at the level of the isthmus. No significant perioperative complications occurred. Two women had two consecutive pregnancies following TCC, so we report the outcome of 16 pregnancies. Fetal salvage increased from 16% before to 94% after TCC. Our experience and an analysis of the available literature support the view that TCC may be a beneficial procedure in women with cervical incompetence due to a severely traumatized cervix.