Pros and cons of additions like ‘Intelligent’ IA
Recently, there has been a tendency to demand detection of more and more
FHR variations.9,14 These can be shown to add
complexity without even theoretical benefits. One proposed ‘intelligent
IA’ (in addition to flawed recommendation of actual ‘counting’) lumbers
additional unproven burden of actively seeking FHR accelerations
(following fetal movements or vaginal/abdominal examination etc.); and
failing that unnecessarily switching over to CTG.7But, the absence of FHR accelerations (especially in low risk cases) is
not in itself pathological even on CTG and hence doesn’t warrant
commencing CTG in the first place.1-4 Thus, one can
safely await detection of late decelerations on IA. Hence, accelerations
need not be actively sought but noted when present only to differentiate
the FHR baseline from them. There is further confused belief that the
type of deceleration cannot be ascertained on IA.9,14When auscultation is only performed towards the end and after the
uterine contraction, the decelerations detected lasting beyond the
contractions are of ‘late’ type by
definition.1,6,15,16 Another recommendation to detect
‘post-deceleration overshoots’ 14 seems a burdensome
distraction, because these are very rare and inconsistent late features
of fetal acidemia even on CTG to be clinically useful.17 A high-quality study of 5388 women showed that out
of 57 babies with cord blood arterial pH below 7.10, none showed
post-deceleration overshoots during labour.17 Hence,
it would suffice just to detect late decelerations and not get
distracted hearing for overshoots. Suggestion to look for quiet and
active epochs (cycling) of FHR 14 for reassurance
seems equally impractical, unproven and un-actionable. The concept of
rise in baseline (within normal range) FHR during labour as an abnormal
finding9 seems to come from uncontrolled unblinded
retrospective reviews of known cases of birth asphyxia with its positive
predictive value unknown (in the absence of persistent late
decelerations). Such creeping additions without good evidence would
increase switch over to CTG and medical intervention.