To review the scientific evidence behind the traditional view that prenatal care improves pregnancy outcomes. The literature published in English between 1965 and 2002 was searched for relevant studies and opinions on prenatal care outcomes. As search engine we used the MEDLINE bibliographic database, employing a combination of keywords, including pregnancy, prenatal care and outcomes. Editorials, proceedings of meetings and reviews, were included in the analysis. This review was not intended to be a systematic or exhaustive review of the literature on prenatal care. The significant heterogeneity of the retrieved papers made any aggregation impossible. In each of the reviewed studies we assessed the methodologic aspects and validity of conclusions, using established criteria for the evaluation of prenatal interventions. Our processing of editorials and other personal opinions was conducted with the intention to draw the line between statements based on scientific evidence and speculative, emotional or traditional concepts. Outcomes research related to prenatal care is marred by methodologic flaws and conceptual problems. While traditional prenatal protocols are based on an individual-centered medical care system, the outcomes are measured using population-based parameters. Interventions capable of improving maternal and neonatal outcomes at the population level are more likely to be social and economic rather than health interventions case by case.