Sonographic visualization of the ovaries throughout pregnancy.

OBJECTIVE: To determine the frequency with which one or both normal ovaries can be visualized during a routine obstetric ultrasound examination. METHODS: The population consisted of 5617 pregnant women at 5.0-39.9 weeks' gestation, studied cross-sectionally. The sonographic visualization rate for one or both normal ovaries, as well as their position above or below the level of the umbilicus, was recorded for one examination in each patient. RESULTS: The study population was divided into three groups according to gestational age: first trimester, 5.0-12.9 weeks; second trimester, 13.0-26.9 weeks; and third trimester, 27.0-39.9 weeks. There were 829, 3195, and 1593 women in the first, second, and third trimesters, respectively. Most women were examined transvaginally in the first trimester; transabdominal sonography was used in the second and third trimesters. The ability to visualize one or both ovaries declined significantly (P < .05) from the first trimester to the second, as well as from the second trimester to the third (P < .001). The percentage of ovaries that were visualized above the umbilicus increased from 2.4% in the first trimester to 10.1% in the second trimester (P < .001), and to 21.7% in the third trimester (P < .001). CONCLUSION: As gestational age advances, there is a significant reduction in the ultrasound visualization rate of normal ovaries. This investigation provides normative data for ovarian visualization throughout pregnancy that may be helpful in establishing ultrasound laboratory standards.

Ratios between the abdominal circumference, head circumference, or femur length and the transverse cerebellar diameter of the growth-retarded and macrosomic fetus.

The purpose of our investigation was twofold: to provide normative data for the ratios between head circumference and cerebellum, abdominal circumference and cerebellum, and femur length and cerebellum; and to evaluate the predictive accuracy of an abnormal ratio in the detection of growth retardation and macrosomia. Data on 675 women with normal gestations between 14 and 42 weeks were used to estimate reference curves for the three ratios to be evaluated. We then compared the ratios of 34 fetuses with intrauterine growth retardation and 28 macrosomic fetuses to the control group. Of the three ratios that we investigated, abdominal circumference to transverse cerebellar diameter was the most efficacious. However, the sensitivity of this ratio for the detection of intrauterine growth retardation and macrosomia was only 52.9% and 46.6%, respectively. A ratio between head circumference, abdominal circumference, or femur length and the transverse cerebellar diameter cannot reliably distinguish between normally growing fetuses and those that are growth retarded or macrosomic.

Subcutaneous tissue thickness cannot be used to distinguish abnormalities of fetal growth.

Two hundred forty-four women with normal pregnancies between 15-42 weeks' gestation served as a control group to determine subcutaneous tissue thickness at three different fetal locations: mid-calf, mid-thigh, and abdomen at the level of the abdominal circumference. The values at the three locations were comparable, varying between 1 mm at 15 weeks' gestation and approximately 5.5 mm at term. Similar measurements were obtained in two study groups consisting of 13 growth-retarded and 38 large for gestational age fetuses. The degree of overlap in subcutaneous tissue thicknesses between the normal group and the two groups with disturbances in fetal growth was such that neither growth retardation nor macrosomia could be reliably predicted with these sonographic measurements.