ABSTRACT. Objective. Healthy People 2010 calls for reductions in rapid repeat births (RRBs), defined as births occurring within 24 months after a previous birth for women of all ages, and prevention of repeat births during adolescence, regardless of the birth interval. Home visiting has been promoted as a mechanism to prevent child abuse and neglect and to improve pregnancy outcomes. This study aims to assess the impact of home visiting in preventing RRB and its malleable determinants and assesses the influence of RRB on the mother and the index child. We hypothesized that maternal desire to have a RRB, access to a family planning site, and use of birth control would be significant malleable determinants and that the effects of the program in preventing RRB would be mediated through its influence on these variables. We also hypothesized that the occurrence of RRB would result in increased stress and family dysfunction, resulting in adverse maternal and child outcomes such as severe maternal stress, maternal neglect of the index child, decreased maternal warmth toward the index child, and increased behavior problems of the index child.Methods. The Healthy Start Program (HSP) is a home visiting program to prevent child abuse and neglect and to promote child health and development among newborns of families identified as being at risk for child maltreatment. This study was a randomized, controlled trial of Hawaii's HSP, in which eligible families were randomly assigned to home-visited and control groups. A total of 643 families at risk for child abuse were enrolled between November 1994 and December 1995. Data to measure RRB and malleable determinants were collected through structured maternal interviews and observation of the home environment. We measured RRB through maternal self-report by asking about a subsequent birth in follow-up interviews at 1, 2, and 3 years. To measure the malleable determinants, we measured the mother's desire for a RRB at baseline and at the 1-year interview and determined whether she had access to a family planning site. The mother was also asked which contraceptive methods she had ever used in the past and which methods, if any, she used in the year following the index child's birth. We measured 3 maternal parenting outcomes at the year 3 follow-up interview, ie, parenting stress, neglectful behavior toward the index child, and warmth toward the index child. We used odds ratios with 95% confidence intervals (CIs) to measure the strength of associations. Multiple logistic regression was used to assess 1) program effects on RRB and its malleable determinants, 2) the impact of the malleable determinants on RRB, and 3) the association between RRB and adverse maternal and child outcomes.Results Conclusions. Overall, 20% of the mothers in our sample of at-risk families had a RRB, which was far greater than the national average of 11%. RRB was associated with a greater likelihood of adverse consequences for both the mother and the index child. The lack of program effects can be traced to sho...