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发帖数: 819 | 1 http://www.sciencedirect.com/science/article/pii/01406736939194
Abstract
Despite widespread application of ultrasound imaging and Doppler blood flow
studies, the effects of their frequent and repeated use in pregnancy have
not been evaluated in controlled trials. From 2834 women with single
pregnancies at 16-20 weeks gestation, 1415 were selected at random to
receive ultrasound imaging and continuous-wave Doppler flow studies at 18,
24, 28, 34, and 38 weeks gestation (the intensive group) and 1419 to receive
single ultrasound imaging at 18 weeks (the regular group). Outcome data was
obtained from 99% of women who entered the study. The only difference
between the two groups was significantly higher intrauterine growth
restriction in the intensive group, when expressed both as birthweight <10th
centile (relative risk 135; 95% confidence interval 1·09 to 1·67; P=0·
006) and birthweight <3rd centile (relative risk 1·65; 95% confidence
intervals 1·09 to 2·49; P=0·020). While it is possible that this finding
was a chance effect, it is also plausible that frequent exposure to
ultrasound may have influenced fetal growth. Repeated prenatal ultrasound
imaging and Doppler flow examinations should be restricted to those women to
whom the information is likely to be of clinical benefit. Lancet 1993, 342:
887–91 |
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