Use of fetal-pelvic index in the prediction of vaginal birth following previous cesarean section

J Obstet Gynaecol Res. 2003 Apr;29(2):104-8. doi: 10.1046/j.1341-8076.2003.00086.x.


Aim: To clarify the usefulness of the fetal-pelvic index as a predictor of vaginal birth after previous lower segment cesarean section.

Methods: One hundred and seventy women with one lower segment cesarean section who attempted for trial of vaginal birth were enrolled. Pelvimetry was performed to measure maternal pelvic inlet and mid-cavity circumferences at 37 weeks gestation. Ultrasound was performed to measure fetal head and abdominal circumferences at 38-39 weeks. The fetal-pelvic index was derived. The predictability of fetal-pelvic index in the predicting the outcome of delivery was calculated.

Results: Fifty-seven (33.5%) women required repeated cesarean section and 113 (66.5%) delivered vaginally. Twenty-two women with positive fetal-pelvic index had repeated cesarean section. The predictability of positive fetal-pelvic index was 48.9%. Ninety of the 125 patients with a negative fetal-pelvic index delivered vaginally. The predictability of negative fetal-pelvic index was 72.0%.

Conclusions: Fetal-pelvic index derived in the antenatal period has low predictive value in predicting of successful vaginal birth after cesarean section. This index is not useful in clinical practice.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Fetus / anatomy & histology*
  • Humans
  • Pelvimetry / methods
  • Pelvis / anatomy & histology*
  • Pregnancy
  • Prospective Studies
  • Ultrasonography, Prenatal
  • Vaginal Birth after Cesarean*