Predictive Value of Midtrimester Universal Cervical Length Screening Based on Parity.

Area of Science:

• Maternal-fetal medicine
• Obstetrics
• Reproductive health

Background:

• Spontaneous preterm birth (sPTB) remains a leading cause of neonatal morbidity and mortality.
• Midtrimester cervical length (CL) measurement is utilized as a screening tool for sPTB.
• The influence of parity on the predictive performance of CL screening is not fully elucidated.

Purpose of the Study:

• To assess how parity affects the performance of midtrimester cervical length (CL) in predicting spontaneous preterm birth (sPTB).
• To compare the predictive accuracy of CL screening for sPTB between nulliparous and multiparous women.

Main Methods:

• A retrospective cohort study included 13,508 women undergoing transvaginal CL screening between 17-23 weeks' gestation.
• Receiver operating characteristic (ROC) curves were analyzed to compare the predictive ability of CL for sPTB.
• Sensitivity, specificity, and predictive values were calculated for various CL cutoffs.

Main Results:

• Nulliparous women had higher sPTB rates (6.5%) and shorter mean CLs (39.9 mm) compared to multiparous women (4.9% and 41.8 mm).
• Midtrimester CL was significantly more predictive of sPTB in nulliparous women (AUC 0.67) than in multiparous women (AUC 0.61).
• Sensitivity for sPTB prediction was lower in multiparas across CL cutoffs, while specificity was comparable.

Conclusions:

• Midtrimester cervical length is a less effective predictor of spontaneous preterm birth in multiparous women compared to nulliparous women.
• The diminished predictive value of CL screening in multiparas raises concerns about the benefit of universal screening in this group.