Prediction of preterm birth using the cervical consistency index

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Diagnostic Imaging

Background:

• Spontaneous preterm birth (PTB) remains a leading cause of neonatal morbidity and mortality.
• Accurate prediction of PTB is crucial for timely intervention and improved outcomes.
• Current methods for PTB prediction have limitations in sensitivity and specificity.

Purpose of the Study:

• To evaluate the diagnostic performance of a novel cervical consistency index (CCI) for predicting spontaneous PTB.
• To establish reference ranges for CCI across different gestational ages.
• To compare the predictive power of CCI with traditional cervical length measurements.

Main Methods:

• A prospective cross-sectional study included 1115 singleton pregnancies (5-36 weeks gestation).
• Cervical consistency index (CCI) was calculated using anteroposterior cervical diameter measurements before and after probe pressure (CCI = (AP'/AP) × 100).
• Transvaginal sonography was used to measure CCI and cervical length; spontaneous PTB outcomes were assessed. Logistic regression and ROC curve analysis were employed.

Main Results:

• The study followed 1031 women, with spontaneous PTB rates of 0.87% (before 32 weeks), 2.13% (before 34 weeks), and 7.76% (before 37 weeks).
• CCI demonstrated a strong inverse linear correlation with gestational age (R²=0.66, P<0.001).
• CCI showed high diagnostic power for predicting spontaneous PTB (AUCs ranging from 0.907 to 0.947), significantly outperforming cervical length.

Conclusions:

• The cervical consistency index (CCI) is a reproducible and effective sonographic marker for predicting spontaneous preterm birth.
• CCI exhibits a clear inverse linear relationship with gestational age.
• This novel index offers superior predictive accuracy for spontaneous PTB compared to conventional cervical length assessment.