Abstract：Objective: To longitudinally investigate maternal left cardiac morphology, function and uterine artery resistances in uncomplicated twin gestations. Methods: Women with twin pregnancies, who were examined and delivered in Beijing Obstetrics and Gynecology Hospital between January 2013 to October 2014, were enrolled prospectively and underwent serial fetal ultrasound examination and maternal echocardiography at 11~14 weeks, 21~26 weeks and 28~34 weeks of gestation. Those with any complications were excluded. Left cardiac morphology, function and uterine artery resistances were assessed longitudinally and compared with those obtained at the same gestational age periods in a group of singleton gestations. Results: There were 50 normal twin pregnancies and 35 singleton pregnancies as controls. In twin pregnancies, left atrial end-diastolic dimensions, left ventricular end-diastolic and end-systolic dimensions showed significant increase throughout the pregnancy period, especially between 11~14 weeks and 21~26 weeks, but the difference was not statistically significant between twin pregnancies and control group. Total vascular resistance(TVR), cardiac output(CO) and heart rate(HR) changed throughout the pregnancy period, especially between 11~14 weeks and 21~26 weeks. E/E' increased throughout the pregnancy period and grew rapidly between 21~26 weeks and 28~34 weeks. Compared with singletons, HR and CO were significantly higher at 21~26 week and diastolic blood pressure(dBp) was significantly higher at 28~34 weeks in twins. Bilateral uterine artery mean pulse index(PI), resistance index(RI) and ratio of peak-systolic to end-diastolic blood flow velocities(S/D) decreased significantly in twins throughout the pregnancy period. The existence of early-diastolic notch decreased significantly especially between 11~14 weeks and 21~26 weeks. Bilateral uterine artery mean PI, RI and S/D at each period and the existence of early-diastolic notch at 11~14 weeks were significantly lower in twins than in singletons(P<0.05). Conclusions: In twin pregnancies, left cardiac dimensions, CO and HR showed significant increase. TVR and uterine artery resistances decreased throughout the pregnancy period, especially between the first and second trimester. Left ventricular filling pressure was growing fast between the second and third trimester.Compared with singletons, HR and CO were significantly higher at the second trimester, dBp was significantly higher at the third trimester in twins, and uterine artery resistance was lower at each time period. The existence of early-diastolic notch was lower at the first trimester.
李晓菲，吴青青. 正常双胎妊娠孕妇左心结构、功能及子宫动脉血流参数纵向研究[J]. 中国临床医学影像杂志, 2016, 27(1): 32-37.
LI Xiao-fei, WU Qing-qing. A longitudinal study of maternal left cardiac morphology, function and uterine artery resistances in#br#
normal twin pregnancy. JOURNAL OF CHINA MEDICAL IMAGING, 2016, 27(1): 32-37.
[1]Bamfo JE, Kametas NA, Nicolaides KH, et al. Maternal left ventricular diastolic and systolic long-axis function during normal pregnancy[J]. Eur J Echocardiography, 2007, 8(5): 360-368.
[2]Robson SC, Hunter S, Boys RJ, et al. Serial study of factors influencing changes in cardiac output during human pregnancy[J]. Am J Physiol, 1989, 256(4 Pt2): H1060-H1065.
[3]Valensise H, Novelli GP, Vasapollo B, et al. Maternal cardiac systolic and diastolic function: relationship with uteroplacental resistances. A Doppler and echocardiographic longitudinal study[J]. Ultrasound Obstet Gynecol, 2000, 15(6): 487-497.
[4]Flo K, Wilsgaard T, Vartun A, et al. A longitudinal study of the relationship between maternal cardiac output measured by impedance cardiography and uterine artery blood flow in the second half of pregnancy[J]. BJOG, 2010, 117(7): 837-844.
[5]Kametas NA, McAuliffe F, Krampl E, et al. Maternal cardiac function in twin pregnancy[J]. Obstet Gynecol, 2003, 102(4): 806-815.
[6]Kuleva M, Youssef A, Maroni E, et al. Maternal cardiac function in normal twin pregnancy: a longitudinal study[J]. Ultrasound Obstet Gynecol, 2011, 38(5): 575-580.
[7]Bhide A, Acharya G, Bilardo CM, et al. ISUOG practice guidelines: use of Doppler ultrasonography in obstetrics[J]. Ultrasound Obstet Gynecol, 2013, 41(2): 233-239.
[8]张运，张梅. 心脏功能测定[M]//王新房. 超声心动图学. 4版. 北京：人民卫生出版社，2009：231-235.
[9]Bamfo JE, Kametas NA, Nicolaides KH, et al. Reference ranges for tissue Doppler measures of maternal systolic and diastolic left ventricular function[J]. Ultrasound Obstet Gynecol, 2007, 29(4): 414-420.
[10]Israel T, Dorit M, Joseph I, et al. Changes in uterine blood flow during human pregnancy[J]. Am J Obstst Gynecol, 1990, 162(1): 121-125.
[11]Gómez O, Figueras F, Fernández S, et al. Reference ranges for uterine artery mean pulsatility index at 11-41 weeks of gestation[J]. Ultrasound Obstet Gynecol, 2008, 32(2): 128-132.
[12]杨怡珂，林建华，林其德，等. 妊娠早中晚期相关动脉血流参数及其规律[J]. 中国实用妇科与产科杂志，2009，25（9）：677-680.
[13]陈倩. 正常单胎及双胎妊娠妇女子宫动脉血流变化的比较[J]. 中华妇产科杂志，1999，34（7）：396-398.
2016, Vol. 27 
