RESUMEN
This study is done for the pulsatility index (PI) and resistance index (RI) of the "umbilical artery" during pregnancy. We determine the normal range (mean+/-2SD) for various indices in our population and statistical significance of these values in pregnancy induced hypertension and small for gestational age (SGA) babies. One hundred twenty random pregnancies were screened at various periods of gestations. A color Doppler scanner with a carrier frequency of 3.5 MHz was used for studying the umbilical artery. Pregnancies with a normal outcome were used for calculating the normal range of various indices and for testing the specificity and negative predictive value (NPV) of the study. Those pregnancies with an abnormal outcome PIH and SGA babies were used for calculating the sensitivity and positive predictive value (PPV) of the study. In normal pregnancies, the flow velocity waveforms (FVWs) showed a good diastolic flow. A low diastolic flow and high indices characterized the pregnancies with abnormal outcomes. Among the umbilical indices, the PI had the highest sensitivity and specificity of 83.33 and 64.28 respectively. Doppler provides a non-invasive method of assessing the fetal and maternal circulation during pregnancy.
