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REVERSE DIASTOLIC WAVE IN UMBILICAL ARTERY.


Reverse Dialistic Wave in Umbilical Artery.

Finding       : 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 adequate  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 weeks.

Reference : clinical applications of Doppler ultrasound by Kenneth J. W. Taylor , Peter N. Burns ,  Peter N. T. Wells.

Submitted by:  Dr M. Adinarayana Rao & Dr. Hemalatha Devi.



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