A NEW FORMULA FOR PRENATAL ULTRASONOGRAPHIC WEIGHT ESTIMATION IN EXTREMELY PRETERM FETUSES

A new formula for the prenatal estimation of the weight of extremely p reterm fetuses was derived using ultrasound measurements and birth wei ghts of 73 premature infants delivered before 30 completed weeks of pr egnancy and weighing between 400 and 1,680 g at birth. The actual birt h weight lay within +/-15% of the estimated weight calculated with thi s formula in 92% of the cases. Preliminary testing of the reliability of the formula was performed on a further test group of 19 nonselected cases. The formula developed in this study offers a reliable and simp le method of prenatal estimation of fetal weight between 23 and 30 wee ks of gestation.