Can sonographic measurements and changes in cervical length during pregnancy predict preterm labour in an asymptomatic low-risk population?

OBJECTIVE

This study measured cervical length (CL) at 14-16 and 21-24 weeks of gestation and assessed whether the difference between the measurements is predictive of preterm delivery (PTD).

METHODS

This retrospective, cohort study included patients with two consecutive CL measured with transvaginal sonography at 14-16 weeks of gestation (CL1) and 21-24 weeks (CL2). Electronic medical records were reviewed for demographic, medical and obstetric history; complications during the current pregnancy and delivery data. CL1, CL2 and the change between scans were evaluated and correlated to PTD prediction.

RESULTS

Among the 216 patients, 196 (90.7%) delivered at term (≥37 weeks) and 20 (9.3%) preterm (<37 weeks). CL1 was not a good predictor of PTD (p = .70). CL2 was significantly shorter in the PTD group (p < .05). The correlation between CL change and PTD was not significant (p = .55). Perinatal outcomes between term and preterm deliveries were similar.

CONCLUSIONS

Sonographic measurement of CL at 14- to 16-week gestation and the difference between CL in the first and second scans are not reliable predictors of PTD. However, cervical length at 21-24 weeks in low-risk women is predictive of this complication.