Impact of the severity of fetal distress on decision-to-delivery intervals for assisted vaginal delivery

Summary

To correlate the severity of fetal distress assessed retrospectively using the Dublin intrapartum fetal monitoring classification, with decision-to-delivery intervals (DDI) and neonatal outcome, a prospective 3-month study of 78 consecutive instrumental deliveries was conducted. There were 66 cardiotocographs (CTGs) with an 83% majority agreement on classification: it was agreed 95% of deliveries should be expedited for the 58 interpretable CTGs. Although the more abnormal CTG patterns resulted in shorter DDIs and greater neonatal acidaemia, there were no significant correlations. Acidosis was present in 14% with a suspicious, or 22% an ominous CTG pattern. Delivery as a trial in theatre doubled the DDI at 41.5 ± 22.7 (mean ± SD) min, compared with 18.1 ± 8.1 min in the labour room (p < 0.0001), with one case of severe acidosis in the former group. The prolonged DDI with a trial of delivery in theatre could adversely compromise the already ‘distressed’ fetus and should be used only when clearly indicated.

Keywords:

• Delivery times
• fetal distress
• forceps
• neonatal acidosis
• ventouse