Study on flow states in normal fetal aortic isthmus by echocardiography / 中华超声影像学杂志

ABSTRACT

Objective To explore blood flow characteristics of normal fetal aortic isthmus (AoI) in different gestational age by fetal echocardiography.Methods Two hundred and sixty-five normal fetuses were enrolled in the study from August 2015 to July 2016.The mean gestational age was (29.35 ± 4.50) weeks,The AoI inner diameter(D),systolic and diasctolic as well as end-systolic velocities (v),end-systolic duration time(t),pulsatility index(PI),resistance index (RI) were measured.The relationship between these parameters and gestational age was plotted by linear regression.Results In normal fetues,there was a short reverse flow at the end of systole and these states could be classified into three categories by gestational weeks(GW)(1) line-like wave (P50 =25.55 GW);(2) incisura wave (P50 =30.10 GW);(3) reverse flow (P50 =35.40 GW).There were good correlation between end systolic v and gestational age (R =0.786,P ＜0.05),as well as D and gestational age(R =0.726,P ＜0.05).The correlation between end systolic t and gestional age was moderate (R =0.518,P ＜0.05).Conclusions A short reverse flow can be the characteristics of normal fetal aortic isthmus,and the end systolic flow increases significantly with the gestational age.These characteristics can provide differential information for abnormal blood flow states.