Ewigman B G, Crane J P, Frigoletto F D, LeFevre M L, Bain R P, McNellis D
Department of Family and Community Medicine, University of Missouri School of Medicine, Columbia.
N Engl J Med. 1993 Sep 16;329(12):821-7. doi: 10.1056/NEJM199309163291201.
Many clinicians advocate routine ultrasound screening during pregnancy to detect congenital anomalies, multiple-gestation pregnancies, fetal growth disorders, placental abnormalities, and errors in the estimation of gestational age. However, it is not known whether the detection of these conditions through screening leads to interventions that improve perinatal outcome.
We conducted a randomized trial involving 15,151 pregnant women at low risk for perinatal problems to determine whether ultrasound screening decreased the frequency of adverse perinatal outcomes. The women randomly assigned to the ultrasound-screening group underwent one sonographic examination at 15 to 22 weeks of gestation and another at 31 to 35 weeks. The women in the control group underwent ultrasonography only for medical indications, as identified by their physicians. Adverse perinatal outcome was defined as fetal death, neonatal death, or neonatal morbidity such as intraventricular hemorrhage.
The mean numbers of sonograms obtained per woman in the ultrasound-screening and control groups were 2.2 and 0.6, respectively. The rate of adverse perinatal outcome was 5.0 percent among the infants of the women in the ultrasound-screening group and 4.9 percent among the infants of the women in the control group (relative risk, 1.0; 95 percent confidence interval, 0.9 to 1.2; P = 0.85). The rates of preterm delivery and the distribution of birth weights were nearly identical in the two groups. The ultrasonographic detection of congenital anomalies had no effect on perinatal outcome. There were no significant differences between the groups in perinatal outcome in the subgroups of women with post-date pregnancies, multiple-gestation pregnancies, or infants who were small for gestational age.
Screening ultrasonography did not improve perinatal outcome as compared with the selective use of ultrasonography on the basis of clinician judgment.
许多临床医生提倡在孕期进行常规超声筛查，以检测先天性异常、多胎妊娠、胎儿生长障碍、胎盘异常以及孕周估计错误。然而，通过筛查检测出这些情况是否会导致改善围产期结局的干预措施尚不清楚。
我们进行了一项随机试验，纳入了15151名围产期问题低风险的孕妇，以确定超声筛查是否能降低不良围产期结局的发生率。随机分配到超声筛查组的妇女在妊娠15至22周接受一次超声检查，在31至35周接受另一次超声检查。对照组的妇女仅在医生确定的医学指征下接受超声检查。不良围产期结局定义为胎儿死亡、新生儿死亡或新生儿发病，如脑室内出血。
超声筛查组和对照组中每位妇女获得的超声检查平均次数分别为2.2次和0.6次。超声筛查组妇女所生婴儿的不良围产期结局发生率为5.0%，对照组妇女所生婴儿的不良围产期结局发生率为4.9%（相对风险，1.0；95%置信区间，0.9至1.2；P = 0.85）。两组的早产率和出生体重分布几乎相同。先天性异常的超声检测对围产期结局没有影响。过期妊娠、多胎妊娠或小于胎龄儿的妇女亚组中，两组的围产期结局没有显著差异。
与根据临床医生判断选择性使用超声相比，筛查超声检查并未改善围产期结局。
