Table 1.

Study criteria.

INCLUSION CRITERIA

EXCLUSION CRITERIA

Control group-singleton pregnancies from 20 weeks up to 33 weeks and 6 days of gestation with fetuses whose sonographic estimated fetal weight and abdominal circumference falls within the 10 to 90th percentile for gestational age. IUGR group-singleton pregnancies from 20 weeks up to 33 weeks and 6 days of gestation with fetuses whose sonographic estimated fetal weight and abdominal circumference falls below the 10th percentile for gestational age. IUGR staging will be based on the following Doppler findings: Stage 0 includes fetuses with normal umbilical artery and middle cerebral artery Doppler indices. Stage I includes fetuses with abnormal Doppler indices of the umbilical artery (increased resistance indices) or middle cerebral artery (cerebroplacental ratio of < 1). Stage II includes fetuses with absent or reversed Doppler flow of the umbilical artery. Stage III includes fetuses with absent or reversed Doppler flow of the a-wave of the ductus venosus.

The presence of any of the following: Chromosomal anomalies Congenital anomalies Premature labor Maternal medical contraindications to the use of electronic devices, such as pacemakers Maternal mental disability, coma or sensorial changes Severe maternal illness