Cervical length should be measured for women with placenta previa: cohort study

To study the relevance between cervical length (CL) and different maternal/neonatal outcomes in pregnancies complicated with placenta previa/accreta.

Three hundred twenty-eight women, who had medically free singleton live pregnancies with the diagnosis of placenta previa and/or accreta, were included and divided regarding their CL into two groups. Threatened preterm labor, maternal tocolysis, multiple gestations, polyhydramnios, ruptured fetal membranes, fetal complications, history of cervical conization, and the presence of cervical cerclage were the exclusion criteria. Demographic data, obstetric history, as well as, the courses of the complicated pregnancies were collected and statistically analyzed.

The short CL group had significantly less distance between the placenta and the internal cervical os (p-value < .001) Also, they showed more ultrasound parameters of complete placenta previa with anterior location (p-value < .001 and .003 respectively) and placental adherence (21.8 versus 41.1%). Women with short cervix had significantly higher rates of preterm birth, antepartum hemorrhage, emergency cesarean sections, intraoperative estimated blood loss, massive bleeding, prevalence of placental adherence and cesarean hysterectomy (p-value < .001 for the entire outcomes). Multivariable binary logistic regression showed that CL (<30 mm) was a significant independent risk factor in prediction of severe hemorrhage, PTB, emergency CS, placental adherence, cesarean hysterectomy (p-value < .001 for adverse maternal outcomes) and low cord Ph (p-value = .016).

Assessment of the cervical length could be a crucial step in the work-up and decision making for pregnancies complicated with abnormally situated and/or adherent placenta as it is strongly associated with a wide range of maternal and neonatal morbidities.