Objectives: To perform a systematic review of published research trials of preconception care services to determine what evidence for effectiveness of care at improving the course of pregnancy or its outcomes has accumulated since the last major review in 1990.
Methods: The review was conducted adapting the systematic methods developed by the Cochrane Collaboration to collect evidence from published clinical research literature with as little bias as possible. The review included literature published after January 1990, and posted on MEDLINE by July 1999.
Results: Although more than 40 preconception risk conditions were searched and 470 articles were abstracted, only four problem areas and 19 research trials met the review criteria. New evidence of effectiveness was found for screening women who are seeking family planning for risk conditions; having sexually active women of reproductive age take dietary folate supplements; and providing women affected by certain metabolic conditions (diabetes and hyperphenylalanemia) with nutrition services.
Conclusions: To help improve pregnancy outcomes MCH professionals need to promote the concept of readiness for pregnancy and help see that women are as healthy and appropriately nourished as possible before they become pregnant.