Prenatal diagnosis (PND) is offered routinely as part of pregnancy care to a large number of women at increased risk of fetal anomalies. Despite an extraordinary growth in the use of PND and significant resource allocation, few studies have examined outcomes of PND counseling, and virtually no research has evaluated the relative efficacy of various approaches to genetic counseling. This study was a randomized trial that compared which counseling methods – individual, group, and use of a decision aid – are effective in PND counseling for women of advanced maternal age (≥35 years) and their partners. Three hundred and fifty-two women and 225 partners completed pre- and post-intervention questionnaires assessing changes in knowledge, decisional conflict, state anxiety, satisfaction, use of PND, and pregnancy outcomes. All participants showed a significant increase in knowledge and a decrease in decisional conflict post intervention. Those in the group intervention showed a significantly greater increase in knowledge than those in the individual counseling intervention. While high levels of satisfaction were reported by all, those in individual counseling were significantly more satisfied than those receiving group counseling or the decision aid. This study has shown unique benefits with each type of intervention such that women and their partners preferred individual genetic counseling, while they learned best in group-counseling sessions, and experienced the least decisional conflict regarding genetic testing with a decision aid.