SALIVARY PROGESTERONE AS A BIOCHEMICAL MARKER TO PREDICT PRETERM BIRTH IN ASYMPTOMATIC HIGH RISK WOMEN

This prospective study was conducted in 90 asymptomatic high risk women attending antenatal clinic in the Institute of Obstetrics and Gynaecology from January 2015 to March 2016. AIM AND OBJECTIVES: 1. To evaluate salivary progesterone as a marker of preterm birth. 2. To compare it with transvaginal cervical length in predicting preterm birth. MATERIALS AND METHODS: The information pertaining to the study like age, height, weight, BMI, socioeconomic status, occupational status, passive smoking, gestational age at delivery, NICU admission and neonatal mortality were collected from the 90 enrolled AN mothers. Two saliva samples were collected at 24 to 28 weeks and then at 29 to 32 weeks, simultaneously with transvaginal cervical length measurement. They were followed throughout the antenatal period for development of exclusion criteria. Details about gestational age at delivery, birth weight, NICU admission and neonatal mortality were collected. RESULTS: Sensitivity and specificity of salivary progesterone in predicting preterm labour, when done between 24 to 28 weeks was 100% and 94.2% respectively when the criterion was set as ≤ 3903pg/ml. The same when repeated between 29 to 32 weeks, sensitivity and specificity was 100% and 100% respectively when the criterion was set as ≤ 2975pg/ml. Sensitivity and specificity for trannsvaginal cervical length in predicting preterm labour was 91.7% and 95.7% respectively at 24 to 28 weeks when the criterion was set as ≤ 3.1cm and 100% and 98.6% respectively, when done at 29 to 32 weeks, and the criterion set as ≤ 2.9cm. There is increased incidence of preterm labour in group with history of passive smoking (66.7% in preterm group and 34.8% in term group. Neonates belonging to preterm birth group had higher incidence of NICU admissions (13.6% in preterm group and 6.2% in term group). Incidence of neonatal mortality is 1.2% in the pretem group which is significant (P=0.016). CONCLUSION: Salivary progesterone levels was a better predictor of preterm labour when compared to transvaginal cervical length as it has better sensitivity and specificity, non invasive, easier sample collection and does not need technical expertise. Salivary progesterone estimation done at 29 to 32 weeks has a better sensitivity and specificity than at 24 to 28 weeks.