Reference values for fetal penile length and width from 22 to 36 gestational weeks.

OBJECTIVE: Current reference range values for fetal penile growth are based on length measurements. However, methodologies for measuring penile length differ among studies and from the standard technique used in children. We propose that the measurement of penile width may aid in its evaluation. The aim of the study was to create normograms for penile length and width. METHODS: A prospective cross-sectional design was used. One hundred male fetuses at 22 to 36 gestational weeks were included. On ultrasound examination, penile length was measured from tip to base, where the penis joins the scrotum. Penile width was measured at the widest point across the penis. Reference values for the 5th and 95th percentiles were calculated for each gestational week. RESULTS: There was a good correlation between gestational age and penile length (R(2) = 0.606) and width (R(2) = 0.683). The percentile of fetal weight estimation independently affected penile length and width. The interobserver correlation coefficient was 0.939 for length and 0.909 for width. CONCLUSION: Reference range values of fetal penile length and width are presented for 22 to 36 weeks of gestation. These values correlate to gestational age and estimated fetal weight percentile. These reference range measurements may help the evaluation of suspected micropenis.

Sonographic evaluation of kidney parenchymal growth in the fetus.

OBJECTIVE: The aim of the study was to establish a nomogram for renal parenchymal thickness throughout pregnancy. METHODS: One-hundred and twenty-eight healthy women with singleton, well-dated, uncomplicated second- or third-trimester pregnancies were prospectively evaluated for renal parenchymal thickness on routine ultrasound scans. The renal parenchyma was measured in transverse and sagittal sections using predefined criteria. RESULTS: There were no differences in anterior or posterior parenchymal measurements in either plane by fetal sex. On sagittal-section analysis, no differences were noted between the right and left kidneys. A nomogram was established on the basis of the findings. The results showed constant linear growth of the fetal parenchyma during pregnancy. CONCLUSIONS: The normal fetal parenchyma grows at a constant, linear rate throughout pregnancy. The nomogram formulated may serve as a basis of future studies of the correlation of parenchymal thickness with postnatal kidney function in fetuses with urinary tract anomalies.

Reference values for gamma-glutamyl-transferase in amniotic fluid in normal pregnancies.

OBJECTIVE: Nonvisualization of the fetal gallbladder by ultrasound poses a diagnostic dilemma. The aim of the study was to establish reference values for the hepatobiliary enzyme gamma-glutamyl-transferase (GGT) in amniotic fluid in normal pregnancies, and to determine the maximal week of gestation in which reference values can be determined. METHOD: A cross-sectional design was used. The study group consisted of pregnant women at 16 gestational weeks or more referred to our ultrasound unit for amniocentesis. Amniotic fluid was assayed for levels of GGT and other hepatobiliary enzymes using the Integra 800 device. The 5th and 95th percentiles for each gestational week were calculated. RESULTS: A total of 263 samples were analyzed. After conversion to log units, enzyme levels showed a good correlation with gestational week (Pearson). The mean values and the 5th and 95th percentiles were calculated for gestational weeks 16 to 22. Beyond 22 weeks, the number of examinations was insufficient for analysis. On multiple regression analysis, log values of alkaline phosphatase, maternal age, and gestational age independently affected log GGT values. Levels of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were too low, and their correlation with gestational week too poor for calculation of reference values. CONCLUSION: GGT reference values in amniotic fluid in normal pregnancies were defined for gestational weeks 16 to 22. These data may be useful for differentiating isolated absence of fetal gallbladder from extrahepatic biliary atresia.