Predictive value of serum IGFBP-3 and transvaginal cervical length measurement for spontaneous preterm birth in...

To determine the predictive value of serum IGFBP-3 in combination with transvaginal ultrasonography cervical length in singleton pregnancies during the 18-23⁺⁶ weeks' gestational period for the prediction of preterm birth.

This prospective observational study included singleton pregnant women who received antenatal care at King Chulalongkorn Memorial Hospital at 18-23⁺⁶ weeks' gestation between December 2022 and April 2024. Cervical length was determined by transvaginal ultrasound and serum was collected to measure IGFBP-3 levels. Demographic data and pregnancy outcomes were recorded.

A total of 176 pregnant women were analyzed. Twelve cases (6.8%) of preterm births were identified. Preterm birth prediction, when using serum IGFBP-3 values greater than 6.9 ng/ml, had a sensitivity of 75%, a specificity of 61.5%, a positive predictive value (PPV) of 12.3% and a negative predictive value (NPV) of 97.1%. When cervical length values less than 37 mm were used, the prediction had a sensitivity of 66.7%, a specificity of 44.6%, a PPV of 8%, and a NPV of 94.9%. When serum IGFBP-3 or cervical length was used to predict preterm birth, sensitivity, specificity, PPV and NPV were 83.3%, 27.1%, 7.6% and 95.7%, respectively.

The use of serum IGFBP-3 levels in combination with cervical length had a good sensitivity to predict preterm birth. While NPV is high, the low PPV limits its standalone use to predict preterm birth.