VIBROACOUSTIC STIMULATION ENHANCES VISUALIZATION OF THE 4-CHAMBER CARDIAC VIEW IN THE 3RD TRIMESTER

The objective of this study was to determine whether vibroacoustic sti mulation would improve the visualization rate of the four-chamber card iac view. Patients between 26 and 42 weeks' gestation were considered to be candidates for this study if the amniotic fluid index (AFI) was between 8.0 and 24.0 cm, no malformations were detected on a careful f etal anatomical survey and a four-chamber cardiac view was not obtaina ble. Once a four-chamber view was considered to be not obtainable due to fetal position, the patient was asked to withdraw a sealed envelope and was assigned to either the study or the control group. The 164 st udy patients received one to three 3-s vibroacoustic stimulations. Fiv e minutes later a second attempt was made to visualize the four-chambe r view adequately. The control group consisted of another 198 subjects in whom a four-chamber view could not be obtained. The control group did not receive vibroacoustic stimulation. A similar 5-min time interv al was allowed to elapse before an attempt was made to visualize the f our-chamber view. The study and control groups were similar with respe ct to fetal presentation, placental location, fetal weight category, b iophysical profile score, gestational age, AFI and estimated fetal wei ght. The rate of the four-chamber view was significantly higher among fetuses receiving vibroacoustic stimulation (20.1%), in comparison to the control group (11.1%) (p=0.019). Successful repositioning was more likely among fetuses with estimated fetal weight between 2251 and 305 0 g, and at a gestational age between 33.1 and 37.0 weeks. We conclude that in a selected group of patients vibroacoustic stimulation can be used to enhance visualization of the four-chamber view.