Joyce Harder

Doppler waveforms in the fetal aorta and umbilical artery in patients with hypertension in pregnancy

Pulsed Doppler ultrasound assessment of blood flow was performed in the fetal aorta and umbilical arteries of 41 patients with hypertension in pregnancy. Patients were grouped according to severity of the hypertension and the presence or absence of chronic hypertension. Doppler abnormalities were seen in two patients with chronic hypertension, both of whom delivered small for gestational age infants. Only one patient with mild to moderate preeclampsia had abnormal aortic Doppler assessment and was also delivered of a small for gestational age infant. The highest number of abnormal Doppler waveforms in both fetal aorta and umbilical artery were found in patients with severe preeclampsia. Abnormalities were detected more frequently in the fetal aorta than in the umbilical artery. Doppler assessment was often abnormal before a nonstress test or biophysical profile. The number of abnormal Doppler values correlated with perinatal outcome in patients with severe preeclampsia.

Pulmonary hypoplasia testing in clinical obstetrics

An ultrasound-based diagnostic test for predicting pulmonary hypoplasia antenatally by measurements of fetal chest circumference was applied prospectively to 45 patients at risk for developing this disorder. The outcome for the newborn infant and the autopsy findings were correlated with the antenatal prediction. The results of this test demonstrated a sensitivity and a specificity of 88% and 96%, respectively. The application of this test to clinical practice is recommended.

Doppler ultrasound prediction of fetal outcome in twin pregnancies

The usefulness of pulsed Doppler ultrasound in predicting twin pregnancies destined for unsatisfactory outcomes was examined in 30 twin pregnancies. Fetal flow velocity waveform analysis (systolic/diastolic ratio and pulsatility index) and quantitative analysis in the descending aorta and umbilical artery demonstrated good sensitivity and specificity when compared with biparietal diameter and abdominal circumference measurements. This technique shows some promise as a useful adjunct in the management of twin pregnancies.

The registry and follow-up of complex pediatric therapies program of Western Canada: a mechanism for service, audit, and research after life-saving therapies for young children.

Newly emerging health technologies are being developed to care for children with complex cardiac defects. Neurodevelopmental and childhood school-related outcomes are of great interest to parents of children receiving this care, care providers, and healthcare administrators. Since the 1970s, neonatal follow-up clinics have provided service, audit, and research for preterm infants as care for these at-risk children evolved. We have chosen to present for this issue the mechanism for longitudinal follow-up of survivors that we have developed for western Canada patterned after neonatal follow-up. Our program provides registration for young children receiving complex cardiac surgery, heart transplantation, ventricular assist device support, and extracorporeal life support among others. The program includes multidisciplinary assessments with appropriate neurodevelopmental intervention, active quality improvement evaluations, and outcomes research. Through this mechanism, consistently high (96%) follow-up over two years is maintained.

Evaluation of fetal cardiac dysrhythmias with two-dimensional, M-mode, and pulsed Doppler ultrasonography

Forty-three patients with fetal cardiac dysrhythmia were referred to a tertiary ultrasound department for further evaluation. The patients were subdivided according to the type of dysrhythmia diagnosed. All patients with irregular fetal heart rate had a good perinatal outcome. Of the six patients with fetal tachycardia, two required in utero therapy with maternal digoxin, and one of these fetuses had a cardiac tumor. The eleven patients with fetal bradycardia had the worst perinatal outcome, with four deaths occurring. The results suggest that all patients with fetal tachycardia or bradycardia should have a complete fetal cardiac assessment in a center experienced with the management of such cases.

Atrial natriuretic peptide production in association with nonimmune fetal hydrops

The presence and elevation of atrial natriuretic peptide in fetuses has not previously been demonstrated. This study of right atrial pacing in fetal lambs demonstrated a threefold to fourfold increase in atrial natriuretic peptide during the production of fetal hydrops. Its rate of return to a normal level paralleled the clearance of fetal hydrops. Its possible role in fetal cardiovascular hemodynamics is discussed.

Congenital heart defects and major structural noncardiac anomalies in Alberta, Canada, 1995–2002

BACKGROUND Although the majority of congenital heart defects (CHDs) occur in isolation, a significant number occur with noncardiac anomalies. This study determined the proportion of noncardiac anomalies among CHD cases in Alberta. METHODS Records of infants and children born in Alberta between January 1, 1995, to December 31, 2002, were searched using multiple sources of ascertainment in addition to the Alberta Congenital Anomalies Surveillance System (ACASS) (Alberta Health and Wellness, 2012). Each case was assigned to one CHD category and was further categorized into one of the following groups: isolated CHD, syndromes, chromosomal, associations and sequences, teratogens, Mendelian, neoplasia, heterotaxy, multiple minor anomalies, and multiple major anomalies. RESULTS Of all 3751 CHD cases (prevalence 12.42/1000 total births: confidence interval, 12.03-12.83), 75% were isolated, 10% had a chromosomal etiology, and 9% had multiple major anomalies. All other categories accounted for <2% each. The most commonly associated major noncardiac anomalies were musculoskeletal (MSK) (24%) followed by anomalies of the urinary tract (14%), gastrointestinal system (GI) (11%), and central nervous system (CNS) (11%). CONCLUSIONS This is both a population-based and clinical study using a classification scheme that could help to determine possible etiologic factors contributing to CHD. By eliminating known etiologies such as chromosomal and single gene, future studies can focus on the remainder to evaluate possible preventive measures. The most commonly associated major noncardiac anomalies involve the MSK system, followed by the urinary, GI, and CNS systems.

Folic acid fortification and the birth prevalence of congenital heart defect cases in Alberta, Canada.

BACKGROUND Congenital heart defects (CHDs) are the most common type of congenital anomaly. The precise etiology is unknown and the development of successful primary prevention strategies is challenging. Folic acid may have a protective role; however published results have been inconsistent. This study examines the impact of mandatory folic acid fortification (FAF) on the prevalence of CHDs. METHODS CHD cases were ascertained using the Alberta Congenital Anomalies Surveillance System, Pediatric Cardiology Clinics, Pathology, and hospital records. The birth prevalence and odds ratios (OR) of isolated CHD cases (i.e., without noncardiac anomalies) were calculated comparing pre-FAF (1995-1997) with post-FAF (1999-2002). RESULTS The prevalence of isolated CHD cases remained relatively unchanged when pre-FAF (9.34, 95% confidence interval [CI] 8.79-9.92) was compared with post-FAF (9.41, 95% CI, 8.93-9.91). Left ventricular outflow tract obstruction (LVOTO) decreased post-FAF (OR, 0.76; 95% CI, 0.61-0.94). Coarctation of the aorta contributed to this decline (OR, 0.55; 95% CI, 0.32-0.92). Atrial septal defect (ASD) (OR, 1.42; 95% CI, 1.13-1.80) and ASD with ventricular septal defect (OR, 1.52; 95% CI, 1.10-2.10) increased post-FAF. The remaining types of CHDs were unchanged. CONCLUSION FAF alone does not have an impact on the prevalence of CHDs as a group and the majority of selected types of CHDs in Alberta. The decrease in LVOTO, particularly coarctation of the aorta, may be due to FAF or other environmental factors. The increase in ASD and ASD with ventricular septal defect may reflect an increase in diagnosis and ascertainment.

In utero evaluation of fetal cardiac structure: A preliminary report

Fetal echocardiography as a tool for the prenatal diagnosis of cardiac structural abnormalities was utilized in 27 consecutive patients who were referred for evaluation. Four abnormalities were recognized prenatally and confirmed postnatally. A fifth was identified postnatally. The sensitivity and specificity of this diagnostic test were 80% and 100%, respectively. The utilization of this tool in a tertiary care setting by an adequately trained team has proved to be helpful and is recommended.