Aim: To evaluate the diagnostic value of vaginal fluid aspartate aminotransferase (AST), free triiodothyronine (T3) and free thyroxine (T4 ) in women with preterm pre-labor rupture of membranes (PPROM).
Methods: A case-control study was carried out of 100 women: 50 with PPROM (study group) and 50 age-, gestational age- and weight-matched women with intact membranes (control group). All women underwent sterile speculum vaginal examination. The vaginal posterior fornix was irrigated and the retrieved fluid was sent for AST, free T3 and free T4 assays.
Results: Median vaginal fluid free T3, free T4 and AST were significantly higher in the PPROM group compared with the control group, with vaginal fluid free T4 having the largest area under the curve on receiver operating characteristic curve analysis (P<0.001). Sensitivity, specificity, positive and negative predictive values for free T3 (cut-off, 1.06 pg/mL) were 88%, 70%, 74.6% and 85.4%, respectively, while those for free T4 (cut-off 0.063 ng/dL) were 86%, 72%, 75.4% and 83.7%, and those for AST (4.5 IU/L) were 56%, 70%, 65.1% and 61.4%, respectively. Vaginal fluid AST had less diagnostic accuracy when compared with either free T3 or free T4.
Conclusions: Vaginal fluid AST, free T3 and free T4 seem to be useful and simple markers in diagnosis of PPROM.
Keywords: aspartate aminotransferase; preterm pre-labor rupture of the membranes; thyroid hormone; vaginal washing fluid.
© 2015 Japan Society of Obstetrics and Gynecology.