[Cervical incompetence in multifetal gestation: diagnosis and prophylaxis].
OBJECTIVE: 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. METHODS: Multifetal pregnancies surveyed with three-dimensional ultrasound and pregnancies treated with cervical cerclage were compared to controls. RESULTS: 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. CONCLUSIONS: 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.