How to reduce fetal scalp blood sampling? A retrospective study
evaluating the diagnostic value of scalp stimulation to predict fetal
acidosis assessed by scalp blood sampling
Abstract
Objective - To compare the Fetal Scalp Stimulation (FSS) to Fetal Blood
Sampling (FBS) as an adjunctive test of fetal wellbeing in labor in
order to reduce Fetal Blood Sampling. Design – A retrospective study
from February to December 2019 Setting – Monocentric study, CHRU Lille
Population - Singleton pregnancy with gestational age of more than 36
weeks, cephalic fetal presentation Methods –191 FBS procedures
performed for non-reassuring fetal heart rate during labor were
included. A gentle digital scalp stimulation was performed for 15
seconds, two minutes before each FBS. It was considered as positive when
accelerations and/or normal variability were elicited. The FBS was
classified as normal when pH was < 7.25. Results - Of the 191
FBS procedures, 163 (85.3%) found a normal pH result, 122 (63.9%) and
154 (80.6%) had an acceleration and a normal variability post-FSS,
respectively. When accelerations were observed after FSS, FBS pH result
was normal in 91.6% cases (95%CI, 85-95). When normal variability was
observed after FSS, FBS pH result was normal in 87.4% cases (95% CI,
81-92). Conclusion - This study suggests that FSS could be an
interesting alternative adjunctive test to FBS as it seems to be
reliable, non-invasive and easy to perform. Thus, FSS could be performed
in the first instance when non-reassuring fetal heart rate is observed
in order to limit FBS only to absence of acceleration after FSS.