Study design of a stepped wedge cluster randomized controlled trial to evaluate the effect of a locally tailored approach for preconception care – the APROPOS-II study

BACKGROUND: In a previous feasibility study (APROPOS) in a single municipality of the Netherlands, we showed that a locally tailored preconception care (PCC) approach has the potential to positively affect preconceptional lifestyle behaviours. Therefore, we designed a second study (APROPOS-II) to obtain a more robust body of evidence: a larger group of respondents, more municipalities, randomization, and a more comprehensive set of (clinical) outcomes. The aim of this study is to assess the effectiveness and the implementation process of a local PCC-approach on preconceptional lifestyle behaviours, health outcomes and the reach of PCC among prospective parents and healthcare providers. METHODS: This study is an effectiveness-implementation hybrid type 2 trial. This involves a stepped-wedge cluster randomized controlled trial design aiming to include over 2000 future parents from six municipalities in the Netherlands. The intervention has a dual-track approach, focusing on both the uptake of PCC among future parents and the provision of PCC by healthcare providers. The PCC-approach consists of 1) a social marketing strategy directed towards prospective parent(s) and 2) a local care pathway to improve interdisciplinary collaboration. Data will be collected before and after the introduction of the intervention through questionnaires and medical records in each of the participating municipalities. The primary outcome of this study is change in lifestyle behaviours (e.g. folic acid use, smoking and alcohol use). Secondary outcomes are pregnancy outcomes (e.g. miscarriage, preterm birth, gestational diabetes) and the uptake of PCC. Moreover, a process evaluation will be performed, providing information on the efficacy, feasibility, barriers and facilitators regarding the implementation of the intervention. DISCUSSION: The APROPOS-II study introduces a locally tailored PCC-approach in six municipalities in the Netherlands that will contribute to the body of evidence regarding the effectiveness of PCC and its implementation. If this intervention has a positive effect on lifestyle behaviour changes, leading to improved pregnancy outcomes and the future health of prospective parents and their offspring, it could subsequently be upscaled to (inter)national implementation. TRIAL REGISTRATION: Dutch Trial register: NL7784 (Registered June 6th, 2019).