应用胎儿超声心动图定量分析卵圆孔瓣运动规律以及卵圆孔瓣宫内早闭的血流动力学特点。

选取2019年11月至2020年6月在北京百子湾和美妇儿医院进行产前检查，胎儿及母体均未发现异常的孕妇102 例为正常组，依据孕龄将正常组分为3组：组A孕28⁺⁰~32⁺⁶周36例，组B孕33⁺⁰~36⁺⁶周32例，组C孕37⁺⁰~40⁺⁶周34例。另选取超声心动图诊断为胎儿宫内卵圆孔瓣早闭且右心增大的孕妇14例为异常组。应用M型超声心动图检测胎儿卵圆孔瓣运动曲线，测量收缩期（S峰）和舒张期（D峰）运动峰值，S峰持续时间（ST），1个心动周期持续时间（T），S峰下降斜率，计算ST/T；应用多普勒超声测量肺动脉瓣、主动脉瓣、动脉导管血流速度，静脉导管阻力指数，脐静脉（腹段）血流速度，跨卵圆孔和下腔静脉入右心房血流速度；应用二维超声测量胎儿卵圆孔径，右心房与左心房横径比值（RA/LA）、右心室与左心室横径比值（RV/LV）。比较并分析各组之间以上参数的差异。

正常组胎儿卵圆孔瓣M型超声心动图特点为卵圆孔瓣运动曲线形成的S峰和D峰皆为向左心房单向运动，S峰最大运动峰值大于D峰。正常胎儿S峰最大运动峰值5~7 mm，平均（6.00±0.96）mm。M型超声心动图测量卵圆孔瓣运动曲线S峰运动最大峰值，卵圆孔瓣早闭组与正常组C比较差异有统计学意义［（3.72±0.54）cm vs （6.17±0.94）cm，P＜0.001］，ST/T卵圆孔瓣早闭组较正常组C减小，差异有统计学意义（0.52±0.86 vs 0.59±0.05，P＜0.001）。卵圆孔瓣早闭组胎儿右心扩大，与正常组C比较，RA/LA增大，2组间差异有统计学意义（1.83±0.21 vs 1.19±0.19，P＜0.001）。正常胎儿跨卵圆孔血流速度低于下腔静脉入口血流速度［（40.9±8.9）cm/s vs（52.5±11.5）cm/s，P＜0.05］，卵圆孔瓣早闭组跨卵圆孔血流速度高于下腔静脉入口血流速度［（47.9±10.6）cm/s vs（43.1±7.4）cm/s，P＜0.05］。脐静脉血流速度正常组C高于卵圆孔瓣早闭组，差异有统计学意义［（24.4±4.47）cm/s vs（20.3±5.00）cm/s， P＜0.05］。

M型超声心动图显示正常胎儿卵圆孔瓣运动曲线有其自身规律和特点，卵圆孔瓣宫内早闭胎儿卵圆孔瓣开放运动减低。应用M型超声心动图对卵圆孔瓣运动及血流动力学特点进行定量分析研究，有助于准确诊断卵圆孔瓣宫内闭合。

To quantitatively analyze the opening of the foramen ovale in the fetal heart in late pregnancy by echocardiography, and to investigate the opening characteristics of the foramen ovale in the late pregnancy and hemodynamic characteristics of premature intrauterine closure of the foramen ovale.

A total of 116 women in late stages of pregnancy were included in Hemei Women's and Children's Hospital from November 2019 to June 2020. They ranged in age from 19-42 years, with an average of 31.6±3.1 years. Echocardiography was used to exclude fetal structural cardiac abnormalities, and 102 normal fetuses was recruited finally. These normal fetuses were divided into three according to gestational period: 28⁺⁰-32⁺⁶ weeks (group A; n=36), 33⁺⁰-36⁺⁶ weeks (group B; n=32), and 37⁺⁰-40⁺⁶ weeks (group C; n=34). In addition, 14 fetuses with premature intrauterine closure of the foramen ovale and right heart enlargement were included as an abnormal group. The indicators of motion curves of the fetal foramen ovale valve were recorded: the amplitude of systolic (S peak) and diastolic (D peak) motion, S peak duration (ST), total cardiac cycle duration (T), slope of S peak decline, and calculated ST/T ratio. Doppler ultrasound were used to measure the pulmonary valve (PV), aortic valve (AV), ductus arteriosus (DA) blood flow velocity, venous catheter resistance index (RI), umbilical vein (UV; abdominal segment) blood flow velocity, and blood flow velocity across the foramen ovale and inferior vena cava into the right atrium. Two-dimensional ultrasound parameters including fetal oval aperture (FO), the ratio of the diameter of the right atrium to that of the left atrium (RA/LA), and the ratio of the diameter of the right ventricle to that of the left ventricle (RV/LV) were also recorded.

The characteristics of M-mode echocardiography of the fetal foramen ovale valve in the normal group were that S peak and D peak formed by foramen ovale valve movement curve had unidirectional movement to the left atrium, and the maximum movement peak and duration of S peak were higher than those of D peak. The maximum movement of S-peak in normal fetuses was 5-7 mm, with an average of (6.00±0.96) mm. The maximum movement peak of s-peak in the foramen ovale valve movement curve measured by M-mode echocardiography differed signficantly between the abnormal group and group C [(3.72±0.54) mm vs (6.17±0.94) mm, P＜0.05]. ST/T ratio in the abnormal group was significantly lower than that in group C (0.52±0.86 vs 0.59±0.05, P＜0.001). The right heart was significantly enlarged and RA/LA was significantly increased in the abnormal group compared with group C (1.83±0.21 vs 1.19±0.19, P＜0.001). The blood flow velocity across the foramen ovale in normal fetuses was lower than that in the inferior vena cava inlet [(40.9±8.9) cm/s vs (52.5±11.5) cm/s, P＜0.05]. The blood flow velocity across the foramen ovale in the abnormal group was significantly higher than that in the inferior vena cava inlet [(47.9±10.6) cm/s vs (43.1±7.4) cm/s, P＜0.05]. UV flow velocity in group C was significantly higher than that in the abnormal group [(24.4±4.5) cm/s vs (20.3±5.0) cm/s, P＜0.05].

M-mode echocardiography showed that the movement curve of the foramen ovale valve in normal fetuses has its own patterns and characteristics, and the opening movement of the foramen ovale valve in fetuses with intrauterine premature closure decreases. Quantitative analysis of movement and hemodynamic characteristics of the foramen ovale valve by M-mode echocardiography is helpful to diagnose intrauterine foramen ovale closure accurately.