Detection of pregnant women at risk of cervical incompetence by transvaginal sonography during straining.

OBJECTIVE: To evaluate the ability of transvaginal sonography (TVS) undertaken, during straining to detect incompetent cervix in pregnant women at risk.

METHOD: Forty-seven pregnant women with risk factor(s) for cervical incompetence and 22 pregnant women (control) were evaluated for cervical changes detected by TVS during rest, transfundal pressure and during the stress induced by straining.

RESULTS: The control group demonstrated no cervical changes. The changes were more significant during straining than with transfundal pressure. In the group with risk factor(s), 48.9% showed negative response and 51.1% demonstrated positive response. The pregnancy outcome was more favourable in the group with negative response (full term pregnancy 82.6% vs 70.8%, preterm delivery 13% vs 16.7% and pregnancy loss 4.4% vs 12.5%).

CONCLUSION: TVS during straining can be applied as a stress test in women at risk for cervical incompetence.