Electronic fetal monitoring in the United States in the 1980s.

OBJECTIVE

To measure the frequency with which electronic fetal monitoring was used for childbirth in United States hospitals in the 1980s and to examine variation in use according to risk factors at labor onset.

METHODS

Two data sets from the National Center for Health Statistics (the 1980 National Natality Survey and the 1988 National Maternal and Infant Health Survey) were used to generate proportional frequencies for electronic fetal monitoring use. These data files are based on representative samples of live births (9941 and 9953, respectively) drawn by probability methods from the entire country during a calendar year. Consistency in the sampling methods and questionnaire procedures, and use of sampling weights, permitted national estimates to be generated.

RESULTS

Use of electronic fetal monitoring increased from 44.6% of live births in 1980 to 62.2% in 1988. In both time periods, low-risk women received monitoring more frequently than did women with risk indicators. Use grew by 64% in low-risk women (from 46.5% in 1980 to 76.3% in 1988) but only by 32% in women with risk conditions at labor onset (from 42.6% in 1980 to 56.2% in 1988).

CONCLUSIONS

Use of electronic fetal monitoring increased during the 1980s, disproportionately so for low-risk women. This trend raises questions about the efficacy of monitoring for improving pregnancy outcomes.