Prenatal assessment of normal fetal humerus volume by three-dimensional ultrasound.

Because fetal humerus dysplasia is associated with a variety of congenital syndromes, prenatal assessment of the fetal humerus growth is very important. The fetal humerus volume is one of the indexes in evaluating the humerus growth, but it has never been studied by 3-D ultrasound (US) in utero. To establish a normal reference chart of the fetal humerus volume for clinical use, we undertook a prospective and cross-sectional study using 3-D US to assess the fetal humerus volume in normal pregnancy. A total of 216 singleton fetuses that ranged between 20 and 40 weeks of gestation and fit the criteria of normal pregnancies were included in this study. Our results showed that the fetal humerus volume is highly correlated with the gestational age (GA). Using GA as the independent variable and the humerus volume as the dependent variable, the best-fit regression equation was humerus volume (mL) = 0.0044GA(2) - 0.0841GA + 0.6874 (r = 0.97, n = 216, p < 0.0001). For clinical use, a chart of normal growth centiles of the fetal humerus volume was then established based on this equation. In addition, the common indexes of fetal biometry, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight, were all highly correlated with the humerus volume (all p < 0.0001). In conclusion, our data of the fetal humerus volume assessed by 3-D US can serve as a useful reference in evaluating the fetal humerus growth during normal gestation.

Prenatal diagnosis of fetal multicystic dysplastic kidney with two-dimensional and three-dimensional ultrasound.

Fetal multicystic dysplastic kidney (MCDK) may have grave prognosis and prenatal diagnosis of MCDK by ultrasound (US) is very important. Traditionally, MCDK is diagnosed by 2-D US. Recently, 3-D US has emerged, and may overcome the weakness of 2-D US. In this series, we retrospectively analysed the cases of MCDK diagnosed by prenatal 2-D and 3-D US from November 1995 to March 2002 to evaluate the prenatal sonographic characteristics of this disease and to compare the efficacy of 2-D and 3-D US. The 2-D assessment included the lesion of MCDK, the amniotic fluid volume and associated anomalies. The 3-D assessment included three-orthogonal multiplanar views and various rendering modes of reconstruction of MCDK. In total, 28 cases were diagnosed by prenatal 2-D and 3-D US. Within the study period, 2-D US detected 100% of MCDK, as did 3-D US, and revealed that left, right and bilateral MCDK were in 46.4%, 28.6%, and 25% of cases, respectively. Oligohydromnios was present in 6 cases (21.4%). In addition, 3-D US showed fetal MCDK vividly and provided a whole view of the disease that assisted comprehension of the severity and extent better than 2-D US. In conclusion, although 2-D US detected all the cases of fetal MCDK in utero as did 3-D US, the 3-D images generated by various rendering modes can further assist in evaluating the severity and extent of MCDK, with a novel view that substantially aids the medical team in prenatal management and the parents in genetic consultation.