THE VALUE OF TRANSVAGINAL ULTRASONOGRAPHIC EXAMINATION OF THE UTERINECERVIX IN PREDICTING PRETERM DELIVERY IN PATIENTS WITH PRETERM PREMATURE RUPTURE OF MEMBRANES

The objective of this study was to compare the value of ultrasonograph ic assessment of the uterine cervix and amniotic fluid tests in the pr ediction of the interval from admission to delivery in patients with p reterm premature rupture of membranes. Ninety-two patients admitted to the hospital for preterm premature rupture of membranes between 24 an d 32 weeks of gestation underwent both transabdominal amniocentesis an d transvaginal ultrasonographic evaluation of the uterine cervix. Amni otic fluid analyses included cultures for aerobic and anaerobic bacter ia, mycoplasmas and ureaplasmas, white blood cell count and glucose an d interleukin-6 determinations. The ultrasonographic variables evaluat ed were cervical length, presence of funneling and cervical index ((fu nnel length + 1)/cervical length). The outcome measure was the interva l from admission to delivery. The median interval from admission to de livery was 4.5 days (range 0-36). An abnormal uterine cervix was assoc iated with a shout rime interval (cervical length less than or equal t o 20 mm, median 2 days, range 0-14 vs. median 6 days, range 0-36; p le ss than or equal to 0.0001; presence of funneling, median 3 days, rang e 1-31 vs. median 8 days, range 0-36; p less than or equal to 0.001; c ervical index > 0.50, median 2 days, range 0-7 vs. median 8 days, rang e 1-36; p less than or equal to 0.0001). However, interleukin-6 concen tration in the amniotic fluid was the best predictor of the interval f rom admission to delivery when compared to the ultrasonographic indice s and to all the amniotic variables considered. Moreover, when a multi ple model was applied the cervical index significantly and independent ly improved the performance of interleukin-6 in the prediction of the interval from admission to delivery. These data suggest that the combi ned use of the amniotic fluid interleukin-6 assay and the cervical ind ex in patients with preterm premature rupture of membranes provides a good prediction of the interval from admission to delivery, thus ident ifying a subgroup of patients at high risk of imminent delivery.