Background / Objectives:
Intrauterine growth restriction (IUGR) is defined on the basis of a weight below the 10th percentile for gestational age. placental insufficiency is a major cause of IUGR. Currently, diagnosis of growth restricted fetuses is dependent on ultrasonography. However, it may be too insensitive to detect early placental dysfunction. Diffusion weight MRI (DWI) has been widely used in early detection of tissue ischemia. The purpose of this study is to evaluate diagnostic value of DWI in early diagnosis of placental insufficiency.
 Patients and Methods:
In this prospective study, 38 pregnant women with gestational age between 25-40 week, suspected for having growth restricted fetus by obstetrician were evaluated by ultrasonography and DWI of placenta. Fetuses with estimated fetal weight of less than 10th percentile for gestational age based on sonography and birth weight of less than 10th percentile were categorized as IUGR group and others as control group. ADC values (Apparent Diffusion Coefficient) were obtained from two different areas on ADC map of placenta for each case.
 Results:
After exclusion of 2 cases due to incompatibility of ultrasound and birth weight findings, 17 fetuses were ultimately categorized as growth restricted and 19 were included in control group. After calculating ADC value by DWI of placenta, mean ADC value of placenta in the IUGR and control group were 1442±197 (mm) ^2/sec and 1643±86 (mm)^2/sec, respectively. ADC values were significantly lower in IUGR fetuses than control group. (P Value < 0.001)
Because of low area under ROC curve, no appropriate cut off point could be determined to have high sensitivity and specificity.
 Conclusions:
IUGR is associated with low ADC value and restricted diffusion in placenta but no appropriate cut off point for ADC value could be suggested for early diagnosing of placental insufficiency.