Does prenatal care improve birth outcomes? A critical review

OBJECTIVE: To evaluate evidence that prenatal care improves birth outcomes. DATA SOURCES: The MEDLINE data base was searched for appropriate studies for the years 1966-1994; a review of published studies was also conducted. METHODS OF STUDY SELECTION: Published observational and experimental studies of prenatal care that met specified criteria were selected. DATA EXTRACTION AND SYNTHESIS: Studies were graded based on the system used by the United States Preventive Services Task Force. Data were assessed using established criteria for the evaluation of prenatal interventions: temporal relationship, biologic plausibility, consistency, alternative explanations, dose-response, strength of association, and cessation effects. Current evidence did not satisfy the criteria. CONCLUSION: Prenatal care has not been demonstrated to improve birth outcomes conclusively. However, policymakers deciding on funding for prenatal care must consider these findings in the context of prenatal care's overall benefits and potential cost-effectiveness. Cost-effective reductions in low birth weight deliveries may be beyond the statistical powers of detection of current studies.