: Severe Oligohydroamniosis &
reverse diastolic wave in Umbilical artery on spectral Doppler.
Diagnosis : Fetus is
at severe hypoxia.
Discussion : Flow can be detected
in umbilical arteries as early as 6-8 weeks but it is systolic only.
By 20 weeks all fetuses should have end-diastolic flow, as pregnancy
progress , there is increasing end- diastolic flow. A mature umbilical artery flow
velocity wave form is usually achieved by 28-30 weeks,
it may be delayed in twins.
Absent end diastolic velocity & systolic diastolic velocity ratio
above 4.5 is
abnormal which represent a failure of development of an
placental vasculature tree. Absent end diastolic velocity is associated
with maternal hypertension & fetal
Trisomies. Absent end diastolic velocity leads to IUGR, fetal
distress, perinatal morbidity & mortality.
When reverse diastolic flow is present, it maybe a clinical emergency
because most these features will die within 2
Reference : clinical
applications of Doppler ultrasound by Kenneth J. W. Taylor , Peter N.
Burns , Peter N. T. Wells.
by: Dr M. Adinarayana Rao & Dr. Hemalatha