Incorporating the four-chamber view of the fetal heart into the second-trimester routine fetal examination

The four-chamber view of the fetal heart is reported to he the most useful view for detecting congenital heart defects. In 7322 non-selected, consecutive pregnancies of women attending a second-trimester (18 weeks) routine ultrasound scanning program, we examined our ability to obtain a four-chamber view in the fetus within the 30 min generally allocated to do the scan and record data. Five trained nurse-midwives performed the examinations between June 1988 and September 1990. In the first part of the study, a four-chamber view could not be obtained in 7%, while in the second part, the failure rate was 4%, which showed a learning effect over time. The demonstration of a four-chamber view was significantly better with a 5 MHz than with a 3.5 MHz transducer. The ability to obtain the four-chamber view improved as the gestational age increased. The main reason for not being able to obtain the four-chamber view with the 3.5 MHz transducer was poor imaging; for the 5 MHz transducer, it was an unfavorable position of the fetus. Education and experience, as well as good equipment, are important factors in obtaining good results. The time spent learning to obtain a four-chamber view reliably was relatively long.