Sonographic estimation of fetal liver weight: an additional biometric parameter for assessment of fetal growth.

Abstract

A single fetal ultrasonogram was obtained between the 20th and 40th weeks of gestation in 327 pregnancies. Fetal body weight was calculated with standard methods and fetuses were classified as appropriate for gestational age (303 fetuses), large for gestational age (four fetuses), or small for gestational age (20 fetuses). Fetal liver weight was estimated on the basis of longitudinal, anteroposterior, and cephalocaudal liver dimensions multiplied by a constant (k) of 0.42 determined experimentally in a previous study of adult livers. Estimated liver weights in appropriate for gestational age fetuses were not statistically different from published standards based on autopsy findings (P < 0.005). Similar findings were obtained in two other normal pregnancies examined serially until delivery. Estimation of fetal liver weight appears to be an accurate and reproducible method and may enhance sonographic assessment of fetal growth abnormalities and conditions with fetal liver involvement.

Volumetric Growth of the Liver in the Human Fetus: An Anatomical, Hydrostatic, and Statistical Study

“…With the use of 2D ultrasound, Gimondo et al [ 15 ] indirectly estimated liver volume by measuring the length and transverse and sagittal diameters of the fetal liver and multiplying them by a constant of 0.42. Chang et al [ 16 ] tested hypothesis whether the liver volume obtained by 2D ultrasound from Gimondo's formula [ 15 ], that is, liver volume = 0.45 × length × transverse diameter × sagittal diameter, is tantamount to that determined directly by 3D ultrasound. As it turned out, a volume constant of 0.42 tenuously reflected direct volumetric determination because of its underestimation of the fetal liver volume.…”

“…To date, however, no nomograms have been computed by means of detailed direct measurements of liver volume in the human fetus. A limited number of articles focused on the liver volume accomplished indirectly by measurements of liver length and transverse and sagittal diameters in accordance with the two empirical formulae: liver volume = 0.45 × length × transverse diameter × sagittal diameter [ 15 ] or liver volume = 0.55 × length × transverse diameter × sagittal diameter [ 16 ]. In the light of the recently published INTERGROWTH-21st Project [ 17 ], in this study we aimed to concentrate on age-specific references for liver volume at varying gestational ages, possible sex differences in liver volume, the 3rd, 10th, 50th, 90th, and 97th smoothed centile curves for the liver volume over time (optimal growth curve), the relationship between liver volumes for the 50th centile measured directly and those calculated indirectly on the base of liver length and transverse and sagittal diameters.…”

Fetal Dose Estimates for 18F-Fluoro-l-Thymidine Using a Pregnant Monkey Model

“…Using estimated monkey fetal weights (Table 1) and estimated liver and body weights of 49 g and 1,642 g, respectively, for a human 6-mo fetus (17), we calculated a total radiation dose to the human fetal liver of 53 ± 0.9 μGy/MBq (196 mrad/mCi) (Table 4), or approximately 9.8 mGy (980 mrad) for a 185-MBq (5-mCi) injection. Although much below the 5- to 10-cGy suggested threshold for fatal and nonfatal malformations or defects in the embryo or fetus, a genetic disease risk estimated to be 0.01%–0.09% per 10 mGy (20) is worthy of careful consideration.…”

“…Fetal liver self-dose was evaluated using the method of Stabin et al (16) and involved a 50-mL sphere to represent the estimated 49-g fetal liver in a 1,642-g human fetus (17). Dose from maternal organs was estimated using the method of Millard et al (18).…”

Role of 3-D Ultrasound in Clinical Obstetric Practice: Evolution Over 20 Years

“…The new constant of 0.55 was determined by polynomial regression, so that fetal liver volume obtained with 2-DUS is similar to that obtained with 3-DUS. The constant of 0.42 was determined by Gimondo et al (1995) in 327 fetuses at 20 to 40 wk of gestation using 2-DUS. Boito et al (2003) assessed fetal liver volume with the multiplanar method and its relation to umbilical venous flow and maternal glycosylated hemoglobin (HbA1c) in pregnancies complicated by diabetes mellitus type I.…”