o_1977r8vv9vk1ts2ms0kd8pksa.pdf

364 D. Maulik, R. Figueroa
clinical indicators do not necessarily reflect chronic
respiratory or nutritive deficit of the fetus. It is important
therefore to consider the efficacy of fetal
Doppler velocimetry also with regard to detecting fetal
hypoxia or asphyxia, although it may not prognosticate
the long-term neurologic outcome of the infant.
This chapter provides a general review of the efficacy
of fetal Doppler velocimetry for predicting adverse
perinatal outcome and identifying fetal hypoxia
and acidosis in high-risk and unselected pregnancies.
The efficacy of the method in relation to specific
pregnancy disorders is considered in other dedicated
chapters in this book.
Doppler Velocimetry
and Adverse Perinatal Outcome
This section presents a critical appraisal of the effectiveness
of fetal Doppler velocimetry for identifying
the fetus at risk. During this inquiry it is important
to ascertain whether the technique is used in complicated
pregnancies or in an unselected obstetric population.
Although such risk categorization is merely a
relative distinction of high or low prevalence of adverse
outcome in population, it significantly influences
the efficacy measures of a test. Thus for a given
diagnostic test, the efficacy is greater among patients
with a high prevalence of the disorder than among
those with a low prevalence. The efficacy of the Doppler
technique should therefore be appraised according
to the risk category of the study population.
Table 24.1. Diagnostic efficacy of umbilical Doppler velocimetry for high-risk pregnancies
Study,
first author
No. of Risk Outcome Prev
patients
(%)
Trudinger [2] 170 GHR SGA < 10th C,
AS 5