How contraceptive use affects birth intervals: results of a literature review.

Short birth intervals can have adverse consequences for maternal and infant outcomes. Optimal birth spacing is often presumed to be achieved through the practice of family planning and use of contraceptives, yet most of the available research does not address explicitly the contribution of contraceptive-method use to birth spacing or maternal and infant survival. We conducted a systematic literature review to assess the body of evidence linking contraceptive use to birth-interval length. Fourteen studies published in English between 1980 and 2008 met our eligibility criteria for inclusion. The findings from these studies are mixed but suggest that the use of contraceptives is protective against short birth intervals. Although results are favorable, many of the studies and methodologies employed are dated. More current research is needed to determine the impact of contraceptive-method use on birth-interval length in order to inform the promotion of family planning for reducing maternal and infant morbidity and mortality through birth spacing.