Routine ultrasound in pregnancy

The interest in studying routine ultrasound in pregnancy has provided useful results that can be applied to practice. There is no consistent evidence of risk caused by ultrasound, neither biologic risk for the fetus nor increased use of health services as a result of ascertained conditions. There is also no consistent benefit to routine ultrasound in terms of important health outcomes. In the United States, this finding may be related to the excellent care provided to women in the usual-care arm of trials and possibly also to practice patterns. For example, with a high background induction rate in the United States, the prevalence of perinatal morbidity from post-term pregnancy may be so low that differences could not be ascertained between routine-ultrasound and usual care arms of the RADIUS study. The evidence from the use of ultrasound to screen for anomalies reveals substantial concern regarding interobserver variability, as might be expected when using a test for screening that requires considerable skill. The range of observed sensitivities underscores the disadvantages of performing basic ultrasound on a routine basis rather than on selected patients. Because routine ultrasound can reduce perinatal deaths in a population of women who would consider pregnancy termination, pretest counseling may identify a subset of women for whom screening may be effective in improving health outcomes. This remains to be demonstrated in the United States.