Salivary progesterone and cervical length measurement as predictors of spontaneous preterm birth

Objective: To evaluate the efficacy of salivary progesterone, cervical length measurement in predicting preterm birth (PTB).

Methods: Prospective observational study included 240 pregnant women with gestational age (GA) 26–34 weeks classified into two equal groups; group one are high risk for PTB (those with symptoms of uterine contractions or history of one or more spontaneous preterm delivery or second trimester abortion) and group 2 are controls.

Results: There was a highly significant difference between the two study groups regarding GA at delivery (31.3?±?3.75 in high risk versus 38.5?±?1.3 in control), cervical length measured by transvaginal ultrasound (24.7?±?8.6 in high risk versus 40.1?±?4.67 in control) and salivary progesterone level (728.9?±?222.3 in high risk versus 1099.9?±?189.4 in control; p?p value 0.035) but not in low risk group (p value 0.492). CL measurement showed a sensitivity of 71.5% with 100% specificity, 100% PPV, 69.97% NPV and accuracy of 83%, while salivary progesterone showed a sensitivity of 84% with 90% specificity, 89.8% PPV, 85.9% NPV and accuracy of 92.2%.

Conclusion: The measurement of both salivary progesterone and cervical length are good predictors for development of PTB.