Comparison of outcomes of Foley’s induced labors with different sonographic floater densities in fore‑water

  • Samartha Ram Hemmanur
  • Sai Samyuktha Illa
  • Hanuman Rama Krishna
Keywords: Amniotic fluid optical density; Foley’s induction of labor; fore‑water scanning; transvaginal ultrasonography.


Background: Onset of spontaneous labor occurs on completion of fetal functional maturity at amniotic fluid optical density (AFOD) 0.98 ± 0.27 (mean ± SD). All three events occurring together at any time from 35 weeks to 42 weeks indicate the individualized term for each fetus. No failures of induction of labor were reported when labors induced at AFOD 0.98 ± 0.27. As AFOD estimation needs invasive amniocentesis, we tried to induce women with liquor with mature AFOD by observing the sonographic appearances of fore‑water by transvaginal sonography.
Methods: In this comparative study, three groups of gestational age and parity matched uncomplicated singleton term pregnant women,  underwent fore‑water trans‑vaginal sonography before induction of labor with Foley’s catheter. Sonographic images were divided into three grades based on floating particle densities. Each group consisted of 20 women with each grade of sonographic images. Uncentrifuged fresh AF samples collected at amniotomy were used for AFOD measurement with colorimeter at 650 nm in all groups. After Foley’s expulsion, labor was augmented with vaginal misoprostol. The mean AFOD values, Foley’s insertion expulsion intervals, Foley’s insertion delivery intervals (FIDI), T misoprostol required, and neonatal respiratory distress were recorded in each group and compared.
Results: In groups 1, 2, and 3, the mean AFOD was found to be 0.29 ± 0.09, 0.68 ± 0.14, and 1.15 ± 0.20, respectively. Mean Foley’s insertion expulsion intervals were 10.57 ± 3.76 h, 5.83 ± 2.24 h, and 4.08 ± 0.86 h, respectively. Mean FIDI were 20.00 ± 6.20 h, 11.22 ± 4.20 h, and 8.95 ± 2.98 h, respectively. The mean numbers of T misoprostol required in each group was 3 ± 1, 2 ± 1, and 2 ± 1, respectively. Significant differences were observed in all outcomes between groups (P < 0.05) favouring inductions with Grade 3 sonographic images.
Conclusion: Labor induction with Grade 3 sonographic images of fore‑water was successful in all women with shorter FIDI, and with better perinatal outcomes.

Key words: Amniotic fluid optical density; Foley’s induction of labor; fore‑water scanning; transvaginal ultrasonography.


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eISSN: 0189-5117