The temporal association of the implementation of a fetal diagnostic and surveillance program and decreased fetal mortality in a private hospital.

The purpose of this study was to determine whether there was a temporal association between the introduction of a Fetal Diagnostic and Treatment Center and changes in fetal mortality. Two consecutive 15-month pre-program periods (periods I and II) were compared with one 15-month post-program period (period III). The fetal death rates for the pre-program periods I (6.16) and II (6.02) were similar, and the combined rate was 6.09. After the introduction of the Fetal Diagnostic and Treatment Center, the fetal mortality rate decreased to 2.31 (period III). When periods I and II were compared with period III, the major decrease (73.8%) in fetal mortality occurred for fetuses of greater than 34 weeks' gestation. The perinatal mortality rate decreased from 8.76 in periods I and II to 4.42 in period III, reflecting the decrease in fetal deaths.

Maternal and fetal blood flow velocity waveforms in patients with preterm labor: relationship to outcome.

Elevated systolic/diastolic ratios obtained by umbilical and uterine velocimetry have been used to predict adverse pregnancy outcome. We performed pretherapy umbilical and uterine velocimetry by means of continuous-wave Doppler ultrasonography on 92 patients who came for treatment in preterm labor. Fourteen (15.2%) and 12 (13%) patients had elevated uterine (greater than 2.6) and umbilical (greater than 3.5) systolic/diastolic ratios, respectively, and 9 (9.8%) patients had both ratios elevated. Overall 17 (18.5%) patients had at least one abnormal systolic/diastolic ratio. Patients with abnormal Doppler waveforms had a significantly shorter gestation, infants with lower birth weights, and a higher incidence of adverse pregnancy outcome as determined by meconium, cesarean section for fetal distress, low 1- and 5-minute Apgar scores, and days in the neonatal intensive care unit, compared with patients with normal systolic/diastolic ratios. There was no significant difference in the ability of uterine, umbilical, or combined velocimetry to predict preterm birth or adverse pregnancy outcome. Doppler studies in preterm labor patients may help to identify patients at increased risk for preterm birth and poor pregnancy outcome. Further studies are warranted to assess its usefulness in the evaluation of these patients.

Doppler ultrasound in the fetus: a review of current applications.

With the recent introduction of Doppler pulsed and continuous wave as well as color-flow mapping, assessment of blood velocity in the human fetus has added a new dimension to fetal assessment. Although investigators initially examined blood flow in the descending aorta and umbilical vein, there was a wide variation in normal values because of the difficulty of accurately measuring the area of the vessels, a requirement for computation of blood volume. Using duplex sector scanners, velocity and blood flow have been obtained from the right and left ventricular chambers and aortic and pulmonic outflow tracts. At the present time the clinical application of the latter measurements is still under investigation. Doppler color-flow mapping appears to be promising for elucidation of abnormal flow in fetuses suspected of having structural and/or functional cardiovascular disease. Because of the difficulty in computing volume flow due to the above mentioned factors, more recently investigators have examined angle independent parameters of blood velocity from the aorta, carotid and umbilical arteries in an attempt to quantify peripheral resistance. This latter technique appears to be promising for elucidation of placental pathology as is found in a number of fetal and placental diseases.

Fetal echocardiography: the prenatal diagnosis of tricuspid atresia (type Ic) during the second trimester of pregnancy.

Fetal echocardiography (real-time and M-mode) was used to evaluate a fetus at 20 weeks of gestation because intermittent bradycardia had been auscultated at 14 weeks of gestation. Real-time examination of the four-chamber view suggested ventricular disproportion with the left ventricle larger than the right, absence of the tricuspid valve, atrial and ventricular septal defects, and normal pulmonic and aortic outflow tracts. M-mode quantitation demonstrated a dilated left ventricle, small right ventricle, dilated mitral valve, hypertrophy of the left ventricular wall, and normal outflow tract dimensions. Following the diagnosis of tricuspid atresia (type Ic), genetic amniocentesis was performed (46,XX). Intrauterine death occurred during the 28th week of gestation. Autopsy confirmed the echocardiographic findings.

Use of femur length as a means of assessing M-mode ventricular dimensions during second and third trimesters of pregnancy in normal fetus.

Eighty-two normal fetuses were scanned from 18 to 41 weeks of gestation. The following M-mode measurements were correlated with the femur length: end-diastolic right ventricular (r = 0.93), left ventricular (r = 0.92), biventricular outer (r = 0.94), and biventricular inner (r = 0.94) dimensions; tricuspid (r = 0.93) and mitral (r = 0.92) valve opening excursion; right (r = 0.76) and left (r = 0.70) ventricular wall thickness; and interventricular septal thickness (r = 0.75). Polynomial regression demonstrated that linear regression best described the data from which the mean and 5% and 95% confidence limits for predicted M-mode measurements were computed for the femur length.