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Updated: Jul 2, 2026

The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo
Published on: August 2, 2017
Fetal blood sampling in labour and the decision to delivery interval
Rajesh Annappa1, David James Campbell, Nigel A B Simpson
1Department of Obstetrics and Gynaecology, St James University Hospital, Leeds, United Kingdom. rajeshannappa@doctors.org.uk
Objective:
To determine the time interval from decision to result for fetal blood sampling (FBS) and the time from an abnormal pH result to delivery of the neonate.
Study Design:
A prospective study of 107 consecutive attempts at FBS on 72 out of 1450 patients in labour from 1st April 2006 to 1st August 2006 at St James University Hospital in Leeds, England. Statistical analysis was performed by using nonparametric tests.
Results:
107 attempts at FBS on 72 cases were reviewed. Overall the median time from decision to the result of FBS was 17min (interquartile range: 11-22min). 27% (19/70) of fetuses had abnormal results and the median time from result to delivery was 21min (interquartile range: 16-25min) in these cases. The median time from decision to perform FBS to delivery was 37min in cases where acidaemia was present. Body mass index (BMI) cervical dilatation and grade of operator were the factors which affected median time from decision to the result of FBS.
Conclusion:
The time from decision to the result of FBS should be considered in the delivery decision-making process in cases complicated by suspected fetal compromise.
