Ultrasonic biophysical measurements in the normal human fetus for optimal design of the monolithic fetal pacemaker.

Ultrasound measurements, including xiphoid-to-pericardial distance and deployment angle, were made on human fetuses as a function of gestational age for the purpose of assessing the likelihood of 3 failure modes of a monolithic fetal pacemaker, including primary positioning failure due to device length and secondary dislodgement failure due to somatic growth. The small variation of the measurements over the gestational age range relevant to device implantation for the major indications of the device (for complete heart block complicated by hydrops and for bradycardia risk after fetal surgery or intrauterine intervention) predicts a small likelihood of these failure modes.

Trends in prenatal diagnosis of critical cardiac defects in an integrated obstetric and pediatric cardiac imaging center.

OBJECTIVE: Prenatal diagnosis of critical (requiring neonatal intervention) cardiac defects (critical congenital heart diseases (CCHD)) improves survival, yet detection of such malformations is poor. Our institution changed its practice and integrated a pediatric cardiologist into the perinatal team. The purpose of this study was to evaluate how this change affected the rate of detected congenital heart disease (CHD) and the diagnostic accuracy. STUDY DESIGN: Obstetrical ultrasounds of mothers at high and normal risk for fetal CCHD at a single center between 1991 and 2001 were reviewed. Rate of detected CCHD, positive predictive values and false positives were compared before and after pediatric cardiology integration. RESULTS: Between the first and second time periods, the rate of detected CCHD increased from 6.8/1000 ultrasounds to 12.9/1000 ultrasounds (p=0.007), and positive predictive value increased from 75 to 96%. CONCLUSION: Collaboration with pediatric cardiology can significantly improve the rate of detected CCHD. These findings have significant implications for sonographer education and patient care.