Abstract
Fetal Doppler has allowed evaluation of the fetus in both physiological and pathological
conditions which has helped in establishing the relationship between Doppler and fetal
oxygenation. It is difficult to define pathological acidosis, but the threshold pH
of <7 is the best independent predictor for unexplained seizures. Most infants tolerate
acidemia well and recover without any remarkable long term sequelae. Worsening umbilical
artery acidosis is directly and adversely related to worsening of neurological outcome,
hypoxic ischemic encephalopathy, and multiorgan involvement with permanent neurologic
injury. Hypoxic ischemic encephalopathy events are not limited to high-risk pregnancies
but may occur in about 50 % of the low-risk population. Combination of low pH at birth
with other abnormal clinical parameters, e.g., requirement for intubation, 5 min Apgar
score ≤5 has 80 % positive predictability of seizures. Predictability of fetal Doppler
examination for asphyxiated fetuses is in the tune of 86 %. High-risk pregnancies
are screened antenatally by fetal Doppler, biophysical profile, and CTG to identify
at-risk fetuses which are confirmed by the ABG analysis of cord blood immediately
after birth. All these noninvasive modalities complement each other to identify, at
the earliest, any clinical deterioration. Isolated abnormal, e.g., absent end diastolic
flow in umbilical artery, abnormal biophysical profile, or nonreactive CTG are not
adequately sensitive in identifying these fetuses which was observed in the present
cohort. Thus, fetal Doppler in combination with biophysical profile supplemented with
cardiotocograph helps in identifying at-risk fetuses for fetal acidosis and encephalopathy
and helps in considering early intervention.
Keywords
Fetal Doppler - Biophysical - Cardiotocograph - Hypoxemia - Acidosis - Apgar score
- Predictability - Seizures
