[Cervical incompetence in multifetal gestation: diagnosis and prophylaxis]

Preterm birth following cervical incompetence threatens infants of multiple gestation. The questions at hand are whether we can validate a sonographic early detection system and if prophylactically intended strategies, such as cervical cerclage, potentially influence pregnancy management and/or perinatal outcome.

Multifetal pregnancies surveyed with three-dimensional ultrasound and pregnancies treated with cervical cerclage were compared to controls.

Volumetry of the cervix was possible in all 34 examinations performed. In contrast, two-dimensional cervical length assessment could not be obtained in 6% because the presenting fetal part obstructed the sonographic plane. Mean cervical length was 28.7 mm (SD 7.7). Mean cervical volume was 30.0 cm3 (SD 16.0). A significant correlation was found between mean two-dimensional cervical length and mean cervical volume as both parameters decreased with gestational age (p = 0.01). Prophylactic cervical cerclage was used in 17% of triplet pregnancies studied at a mean gestational age of 16 + 2 weeks (98-138 days). In 50% of the quadruplet/quintuplet pregnancies studied, the cerclage was performed at a mean gestational age of 15 + 2 weeks of gestation (78-152 days). The time interval from operation to delivery was 106 days (62-119) for triplets and 96 days (57-142) for quadruplets/quintuplets. Prophylactic cervical cerclage did not prolong pregnancies compared to controls. With respect to the need for hospitalization or intravenous tocolysis or perinatal outcome parameters, no benefit was achieved.

The results disclaim a positive impact of prophylactic cervical cerclage on the course of a multifetal pregnancy and/or perinatal outcome. On the other hand, early non-invasive diagnosis of cervical incompetence enables a risk-adapted conservative pregnancy management.