Obstetric management of incompetent cervix and bulging fetal membranes

To evaluate the effect of emergency cerclage on perinatal outcome in patients with incompetent cervix.

In this descriptive retrospective study, the charts of all patients admitted from 1985 to 1992 with a diagnosis of incompetent cervix and cervical dilatation > or = 2 cm were reviewed. Cervical dilatation at the time of cerclage placement, subsequent pregnancy duration and neonatal outcome were analyzed. Statistical analysis was performed using the paired Student t test.

During the eight-year period, 42 patients were admitted with a diagnosis of incompetent cervix, cervical dilatation > or = 2 cm, and underwent emergency cerclage. Cerclage resulted in a median (range) continuation of pregnancy of 30 (2-102) days. In 20 of these patients the membranes were not bulging through the external cervical os, and pregnancy was extended a median of 50 (30-102) days. The remaining 22 patients presented with membranes bulging into the vagina, and emergency cervical cerclage resulted in a median pregnancy extension of 16 (2-98) days. Parturients with bulging membranes were then analyzed according to cervical dilatation. Cerclage success was significantly lower when attempted at a cervical dilation > or = 4 cm. Median pregnancy duration was 6 (2-15) versus 21 (5-98) days in patients with cervical dilatation < 4 cm.

The results of this study support emergency cerclage in patients without bulging membranes. The data do not support the use of emergency cervical cerclage in patients with bulging membranes and dilatation > or = 4 cm. In those patients, the use of cerclage should be individualized.