Prediction of Intrauterine Growth Restriction in High Pulsatility Index of Uterine Artery

Introduction: Intrauterine growth restriction is a significant cause of neonatal mortality. The uterine artery Doppler waveform becomes transformed into a high flow with low resistance at 22-24 weeks. The apt way to reduce intrauterine growth restriction is to identify the antenatal factors, which ascertain the uterine milieu and nutrient bioavailability. This study was conducted to outline the relation between abnormal uterine artery flow and resultant intrauterine growth restriction in a tertiary care center.

Aim and Objectives: To study the Maternal risk factors and uterine artery Doppler waveform in singleton mid trimester pregnancy and predict the occurrence of intrauterine growth restriction.

Materials and Methods: This prospective study involved Doppler ultrasound examination of the uterine arteries at 20-23 weeks gestation in 697 women with singleton pregnancies attending a routine target scan. Intra Uterine Growth Restriction (IUGR) was recorded in 32 pregnancies.

Results: High Pulsatility Index (PI) (>95th percentile) as compared to low pulsatility Index confers a significant risk (31.58% v/s 2.19%) for Intrauterine Growth Restriction (p<0.05). Presence of high pulsatility is a significant risk factor for early onset IUGR as compared to late onset IUGR.

Conclusion: Abnormal Doppler waveforms within the uterine arteries are indicative of elevated resistance. The perfusion at the trophoblast-maternal interphase is high velocity, low volume and intermittent, resulting in intrauterine growth retardation. This subsequently leads to the damage of fetal tertiary stem villi floating in the intervillous space. The sensitivity is better for early onset IUGR. This study concludes that high pulsatility index in uterine arteries can lead to intrauterine growth restriction. The plausible explanation is reduced Vascular Endothelial Growth Factor (VEGF) from maternal decidual natural killer cells.