Influence of fetal hiccups on Doppler blood flow waveform of fetal arteries: Difference among arteries.

BACKGROUND

A few studies have been reported on the influence of fetal hiccups on umbilical artery. The aim of this study is to clarify the influence of fetal hiccups on Doppler blood flow waveform (DBFW) of some fetal arteries, and to show the difference in these influences among fetal arteries.

OBJECTIVE

DBFW of umbilical artery, descending aorta, and middle cerebral artery were recorded at hiccups in normal fetuses between 34th and 40th gestational weeks. The changes on DBFW were classified into three shapes by the direction and the size of the changes. Shape 1: sharp decrease but not to the baseline, Shape 2: sharp decrease to the baseline (absence), and Shape 3: reverse flow.

RESULTS

At all hiccups, the changes on DBFW of these arteries were observed. These changes were classified into three shapes. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of the descending aorta and middle cerebral artery were Shape 3 whenever the hiccup occurred during cardiac cycle.

CONCLUSION

The changes on DBFW of fetal arteries were observed at all hiccups. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of descending aorta and middle cerebral artery were Shape 3. This is the first study clarified the influence of fetal hiccups on DBFW of some fetal arteries, and showed the difference in these influences among fetal arteries.