Introduction: Integrated care is considered to be a means to reduce costs, improve the quality of care and generate better patient outcomes. At present, little is known about integrated care in maternity care systems. We developed questionnaires to examine integrated care in two different settings, using the taxonomy of the Rainbow Model of Integrated Care. The aim of this study was to explore the validity of these questionnaires. Methods: We used data collected between 2013 and 2015 from two studies: the Maternity Care Network Study (634 respondents) and the Dutch Birth Centre Study (56 respondents). We assessed the feasibility, discriminative validity, and reliability of the questionnaires. Results: Both questionnaires showed good feasibility (overall missing rate < 20%) and reliability (Cronbach’s Alpha coefficient > 0.70). Between-subgroups post-hoc comparisons showed statistically significant differences on integration profiles between regional networks (on all items, dimensions of integration and total integration score) and birth centres (on 50% of the items and dimensions of integration). Discussion: Both questionnaires are feasible and can discriminate between sites with different integration profiles in The Netherlands. They offer an opportunity to better understand integrated care as one step in understanding the complexity of the concept.