Beta-HCG Concentration in Vaginal Fluid: Used as a Diagnostic Biochemical Marker for Preterm Premature Rupture of Membrane in Suspected Cases and Its Correlation with Onset of Labour.

OBJECTIVES: To evaluate β-hCG concentration in vaginal fluid as a biochemical marker for PPROM in suspected cases and its correlation with onset of labour.
MATERIALS AND METHODS: This is a prospective case-control study carried out in tertiary care centre in 1 year. Total 150 pregnant women of gestational age 28-36 week + 6 days were included and were divided into two groups: control (Group 1) (n = 50) normal antenatal patients. Group 2 cases with history of leaking per vaginum subdivided into two groups-Group 2A-(n = 50) with no detectable leakage of amniotic fluid present on per speculum examination and Group 2B-(n = 50) with minimal leaking per vaginum present upon per speculum examination (frank leaking were excluded). β-hCG level was measured by chemiluminescent microparticle assay, and all women were followed till onset of labour.
RESULTS: Mean β-hCG level in vaginal fluid was measured as 6.10 ± 8.52 mIU/mL, 57.10 ± 30.86 mIU/mL and 111.35 ± 36.01 mIU/mL in Group 1, Group 2A and Group 2B, respectively. By taking 21.5 mIU/ml as cut-off, receiver operating characteristic curve shows sensitivity 100%, specificity 92.0%, positive predictive value 92.6%, negative predictive value 100% and diagnostic accuracy 96%. Regarding the correlation of β-hCG level with onset of labour if the β-hCG level is < 21.5 mIU/ml, 100% pregnancy continued beyond 4 weeks and 56% women delivered within 4 weeks when β-hCG level is > 75 mIU/ml.
CONCLUSION: β-hCG in vaginal fluid is a reliable biochemical marker for diagnosing suspected cases of PPROM and is well correlated with onset of labour. © Federation of Obstetric & Gynecological Societies of India 2020.