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Objective: The purpose of this study was to evaluate the frequency with which 6 different fetal cardiac views taken during a fetal ultrasound examination at 18 to 22 weeks' gestation can be obtained satisfactorily for cardiac anomaly screening using either a 2-dimensional (2D) static or 3-dimensional (3D) fast acquisition technique., Methods: A prospective study of 100 low-risk women undergoing an anatomic survey was performed. Standard static 2D and 3D fast acquisition volumes were obtained on all patients. The 2D and 3D images were assigned, in a random order, to be independently graded by 3 reviewers. The degree of inter-reviewer agreement was assessed through the use of the Cohen kappa statistic. The factors contributing to satisfactory imaging were evaluated by random effects logistic regression., Results: A significant proportion of both 2D and 3D images were judged unsatisfactory for screening purposes. However, 2D images were significantly more likely, for all cardiac views, to be judged satisfactory (P < .05). The odds ratios for the 2D technique's being more likely than the 3D technique to provide images satisfactory for screening were 2.6 for the 4-chamber view, 2.4 for the right ventricular outflow tract, 4 for the left ventricular outflow tract, 3.2 for the 3-vessel view, 8.6 for the aortic arch, and 2.2 for the ductal arch., Conclusions: In this prospective study, static 2D imaging was significantly more likely than fast acquisition 2D imaging to yield cardiac views of high enough quality to satisfactorily screen for anomalies.

Objective: The four-chamber view of the heart is an important component of the ultrasonographic examination of the fetus. However, during the second trimester of pregnancy the fetal heart cannot always be imaged in every patient. The purpose of this study was to ascertain the rate of successful imaging of the fetal heart during the second trimester and to determine factors that may influence imaging., Methods: Seven hundred and nine second trimester fetuses were examined and an attempt was made to obtain the four-chamber and outflow tract views of the heart. Analysis included multiple logistic regression models of the main effects and interactions of ten candidate variables., Results: The four chambers and outflow tracts were imaged in 643 fetuses (90.7%) and not imaged in 66 (9.3%). Fifty-two of 709 patients (7.3%) had had previous surgery. In the 52 patients with a history of previous surgery, the heart could not be imaged in 18 (34%). Six hundred and fifty-seven patients (92.7%) did not have previous surgery. Of this group, the fetal heart could not be imaged in 48 (7.3%). In only one fetus in which the heart could not be imaged was it because of fetal position. Three independent risk factors that influenced imaging of the fetal heart were gestational age, maternal adipose tissue thickness, and previous lower abdominal surgery. Increasing gestational age increased the probability of imaging the heart, whereas increasing adipose tissue thickness and a history of previous surgery decreased the probability of imaging the heart., Comments: When the fetal heart cannot be imaged during the second trimester, these factors should be identified. Using data from this study, the gestational age at which the highest probability of imaging the heart can be determined if the thickness of the adipose tissue and a history of lower abdominal surgery are known.

This study examined whether there were differences between the umbilical artery systolic-diastolic (S/D) ratio and resistance index (RI) in patients with normal fetuses living at sea level (group I) and those living between 4,200 and 4,500 feet above sea level (group II). Linear regression demonstrated a significant association (P less than 0.001) between gestational age and the S/D ratio and RI for groups I (n = 100) and II (n = 128). Least-squares regression analysis demonstrated no significant differences in slopes or intercepts between groups I and II. The results would suggest that altitude, up to 4,500 feet above sea level, does not affect umbilical artery Doppler resistance in normal fetuses.

One consequence of the development of the use of ultrasound in obstetrics is the multiplication of parameters studied by the ultrasonographer. This has prompted the development of expensive computerized systems to assist the person doing the examination in evaluating his results. A program designed to be used with a relatively inexpensive, hand-held calculator is described. It gives the gestational age corresponding to the most commonly measured dimensions, the estimation of fetal weight of the examined fetus, and numerous other parameters used in clinical interpretation of ultrasound examinations.

Peak systolic (S) to lowest end-diastolic (D) ratios (S/D) of umbilical velocimetry have been used to assess downstream placental vascular resistance and predict adverse pregnancy outcome. The purpose of this study is to assess S/D ratios in patients undergoing cesarean section for clinical fetal distress. Fifty-six patients were identified who had umbilical velocimetry performed during antepartum fetal surveillance (nonstress testing and amniotic fluid index) within 7 days of undergoing cesarean section for fetal distress at Women's Hospital (Los Angeles, CA). The mean gestational age at delivery was 36.5 +/- 2.5 weeks. Thirty (53.6%) patients had elevated S/D ratios (greater than 3), 24 (42.9%) had abnormal amniotic fluid indices, and 20 (35.7%) had abnormal nonstress testing. Group 1 (N = 30) patients delivered small-for-gestational-age (SGA) fetuses and group 2 (N = 26) patients delivered appropriately grown (AGA) fetuses. In group 1, 24 (80%) patients had abnormal S/D ratios and 16 (53.3%) had abnormal amniotic fluid indices, compared to only 6 (23.1%) with abnormal S/D ratios and 8 (30.8%) with abnormal amniotic fluid indices in group 2 (p less than .05). In contrast, 14 (53.8%) of the 26 patients in group 2 had abnormal nonstress testing compared to only 6 (20%) of the 30 patients in group 1 (p less than .05). Eighteen (69.2%) of the 26 patients in group 2 were post-term pregnancies; 20 (66.7%) of the 30 patients in group 1 had chronic hypertension, pregnancy-induced hypertension, or superimposed preeclampsia.(ABSTRACT TRUNCATED AT 250 WORDS)

In a recent report it was suggested that the transverse diameter of the fetal heart measured randomly during the cardiac cycle from the real-time image was useful in predicting congenital heart disease (Jeanty P, Romero R, Cantraine F, et al: Fetal cardiac dimensions: a potential tool for the diagnosis of congenital heart disease. J Ultrasound Med 3:359, 1984). Comparing the above approach with M-mode measurements at end-diastole and end-systole suggests that random measurement of the transverse diameter is not appropriate for fetal cardiovascular evaluation because it could predict over 40 per cent of normal fetuses to have an "abnormally" increased cardiac dimension.

Eighty-two normal fetuses were scanned from 18 to 41 weeks of gestation. The following M-mode measurements were correlated with the abdominal circumference: diastolic biventricular outer (r = 0.951) and inner (r = 0.948) dimensions; diastolic right (r = 0.942) and left (r = 0.925) internal dimensions; tricuspid (r = 0.916) and mitral (r = 0.900) valve opening excursions; and right (r = 0.774), left (r = 0.731), and interventricular septal (r = 0.753) wall thickness. Polynomial regression demonstrated that linear regression best described the data from which the mean and 5 per cent and 95 per cent confidence limits for predicted M-mode measurements were computed for the abdominal circumference between 12 and 35 cm.

Real-time ultrasonography permits an accurate diagnosis of intrauterine fetal death by documenting absent cardiac motion. Occasionally, intravascular and/or intracardiac gas arises from maceration following fetal demise. The presence of gas in the heart and circulatory system alters the ultrasonic appearance of the fetal body. What may appear to be technically poor visualization of the fetus secondary to tissue maceration, oligohydramnios, or maternal factors may, in fact, be due to reverberation artifacts produced by intravascular gas. These characteristic echogenic foci have been radiographically proven to represent intrafetal gas. Recognition of the appearance of gas in the circulatory system is important since gas is a pathognomonic sign of fetal death.

A correlation has been suggested between impaired fetal growth and preterm delivery. To further investigate this possibility, the femur length/abdominal circumference ratio (FL/AC) was used as a gestational-age independent index of fetal growth in 82 patients admitted because of preterm labor. Of these patients, 43 delivered at term; tocolysis was unsuccessful in 39 patients who delivered preterm. The FL/AC was significant larger in the group with unsuccessful tocolytic therapy compared with the successfully treated group, 23.6 +/- 2.6 vs. 21.3 +/- 1.3 (mean + SD), respectively (P less than 0.001). These results indicate that preterm delivery may be associated with suboptimal fetal growth.

The purpose of this study is to assess alterations in vascular resistance as measured by Doppler ultrasound in the postterm fetus. Forty-five postterm patients (greater than or equal to 287 days gestation by "good" dates) underwent Doppler velocimetry and calculation of systolic to diastolic (S/D) ratios of the umbilical, internal carotid, and uterine artery waveforms within 7 days of delivery. Patients were divided into two groups. Group 1 consisted of 26 patients with normal antepartum fetal surveillance that included reactive nonstress test and an amniotic fluid index (using the four-quadrant technique) equal to or greater than 5 cm. Group 2 consisted of 19 patients with antepartum compromise on the antepartum fetal surveillance tests. There was significantly greater (p less than .05) morbidity in group 2 compared to group 1 as judged by cesarean section for fetal distress (47% vs 15%), meconium at delivery (53% vs 4%), and 5-minute Apgar score less than 7 (30% vs 4%). There were no significant differences in the umbilical and uterine artery S/D ratios in the two groups, although patients in group 2 had significantly lower cerebral S/D ratios (3.6 +/- .5) compared to group 1 (4.4 +/- 0.4) (p less than .05). The ratio of cerebral to placental (umbilical) resistance in group 2 was significantly lower (1.1 +/- .3) compared to group 1 (1.8 +/- .3) (p less than .05). There was a low incidence of abnormal umbilical (greater than 3) and uterine (greater than 2.6) S/D ratios in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

The accuracy of estimating fetal weight (EFW) by ultrasonographic techniques was analyzed after spontaneous premature rupture of the membranes (SPROM). The birth weights of 50 infants with SPROM delivered within 72 hours of ultrasound examination were compared with EFW based on ultrasonically measured parameters. The results indicate that EFW significantly underestimates birth weight in SPROM. The EFW based on biparietal diameter and abdominal circumference underestimated actual birth weight by an average of 12.4 per cent; EFW based on abdominal circumference alone, and on abdominal circumference and femur length, underestimated birth weight by 7.1 and 13.2 per cent, respectively.