Randomised controlled trial of ultrasonographic screening in pregnancy.

510 of 1009 pregnant women in the Trondheim area (Norway) were randomly selected for ultrasound examination at the 19th and 32nd weeks of pregnancy in addition to routine antenatal care. Among the screened women, twins were diagnosed earlier and there were slightly fewer post-term inductions (2.8% versus 4.0%) and fewer low-weight births (2.2% versus 3.6% less than 2500 g), but none of these differences was statistically significant. There were no differences in the condition of the newborn. Small-for-gestational-age births were more often diagnosed antenatally in the screened group and the mothers received more active treatment. During pregnancy, screened women were admitted to hospital more often than unscreened women (15.5% versus 9.2%). The study revealed no adverse short-term biological effects from ultrasound. The cost of the screening programme, including associated costs such as extra hospital admissions, was about US$ 250 per pregnancy.

Fetal and maternal aortic flow in two different maternal positions. An investigation with combined Doppler-velocimetry and ultrasonic multiple array.

To study aortic velocities in the fetus, a newly developed multirangegated Doppler velocimeter was combined with a commercial B-mode linear-array apparatus. Spectrum analysis of the Doppler shift signals was performed. The signals with the highest frequencies were selected for hard-copy, and integrated with a digitizer. In the first part of the study, the reproducibility of the method was established by serial measurements of aortic velocity in 7 near-term fetuses. It proved sufficient to evaluate 5 successive heart-cycles. The mean coefficient of variation was 5% (mean number of recordings evaluated 7.5). In the second part of the study, possible influence of aortocaval compression on fetal aortic velocity indicative of changes in fetal cardiac output, was investigated in 10 pregnant women with no symptoms of supine hypotension. Doppler monitoring of the material cardiac output from the suprasternal notch was added to the set-up described to study the supine reduction of cardiac output frequently described in pregnant women. No significant change was found either in the maternal or in the fetal circulation.