【摘要】 目的 拟初步建立孕28~34周的双胎胎儿生长参数超声测量值的正常范围，比较晚孕期单、双胎妊娠胎儿的宫内生长发育模式。 方法 对2009年5月-2010年4月超声诊断为正常宫内双活胎、单活胎孕妇，采用超声测量胎儿相关生长发育指标，包括双顶径、头围、腹围、股骨长等，测量其中部分双胎的小脑横径并应用虚拟器官计算机辅助分析技术测量其小脑容积，比较晚孕期单、双胎胎儿生长发育的差异。 结果 ①自妊娠30周以后，双胎胎儿的双顶径发育速度比单胎胎儿延缓，单、双胎胎儿平均每周增长分别约2.3、1.7 mm；②自妊娠32周以后， 双胎胎儿的头围的发育速度比单胎胎儿延缓，单、双胎胎儿平均每周增长分别约6.7、5.8 mm；③自妊娠30周以后， 双胎胎儿的腹围的发育速度比单胎胎儿延缓，单、双胎胎儿平均每周增长分别约6.9、5.3 mm；④双胎胎儿股骨长从孕28~34周发育速度均较单胎胎儿缓慢，单、双胎胎儿平均每周增长分别约2.0、1.7 mm；⑤多元分析孕28~34周的双胎胎儿双顶径、头围、腹围和股骨长，相对于单胎胎儿而言，自28周起，双胎妊娠胎儿的生长发育较延缓；⑥自孕28~34周，双胎胎儿小脑横径、小脑容积与单胎胎儿无明显差异。 结论 双胎妊娠胎儿与单胎妊娠胎儿在晚孕期有着不同的生长发育规律。【Abstract】 Objective To initially establish the growth parameters of normal twin pregnancy in 28-34 gestational ages according to the ultrasound measurement, and to compare the intrauterine growth patterns between the singleton and twin pregnancy. Methods The relevant index of the twin pregnancy, including the biparietal diameter (BPD), femur length, head circumference (HC), abdominal circumference (AC), were measured. The transverse cerebellar diameter (TCD) was measured and the virtural organ computer-aided analysis was used to detect the fetal cerebellar volume (FCV). The intrauterine growth patterns between the singleton and twin pregnancy was compared. Results After the gestational age of 30 weeks, the mean values of BPD of the twins pregnancies (1.7 mm) were lower than those of the singleton pregnancies (2.3 mm). After the gestational age of 32 weeks, the mean value of HC of the twins pregnancies (5.8 mm) was lower than that of the singleton pregnancies (6.7 mm). After the gestational age of 30 weeks, the mean values of AC of the twins pregnancies (5.3 mm) were lower than those of the singleton pregnancies (6.9 mm). After the gestational age of 28 weeks, the mean value of FL of the twins pregnancies (1.7 mm) was lower than the singleton pregnancies (2.0 mm). After the gestational age of 28 weeks, the growth of twin pregnancy fetuses is more slowly. After the gestational age of 28-34 weeks, the differences in mean values of TCD and FCV between the twin pregnancy and singleton pregnancy was not significant. Conclusion The twin pregnancy and singleton pregnancy have different growth patterns in the third trimester pregnancy.