Background The number of women of childbearing age with Type 2 diabetes(T2DM) is increasing, and they now account for > 50% of pregnancies in women with pre-existing diabetes. Diabetes pregnancies without adequate pre-pregnancy care have higher risk for poor outcomes (miscarriages, birth-defects, stillbirths) and are associated with increased complications (caesarean deliveries, macrosomic babies, neonatal intensive-care admissions). The risks and costs of these pregnancies can be reduced with pregnancy preparation (HbA1c, ≤ 6.5%, 5 mg folic acid and stopping potentially harmful medicines). However, 90% of women with T2DM, most of whom are based in primary care, are not adequately prepared for pregnancy. This study will evaluate a programme of primary care-based interventions (decision-support systems; pre-pregnancy care-pathways; pregnancy-awareness resources; professional training; and performance monitoring) to improve pregnancy preparation in women with T2DM. Methods The study aims to optimise the programme interventions and estimate their impact on pregnancy preparation, pre-pregnancy care uptake and pregnancy outcomes. To evaluate this multimodal intervention, we will use a multi-method research design following Complex Adaptive Systems (CAS) theory, refining the interventions iteratively during the study. Thirty GP practices with ≥ 25 women with T2DM of reproductive age (18–45 years) from two South London boroughs will be exposed to the intervention. This will provide > 750 women with an estimated pregnancy incidence of 80–100 to study. The research involves: a clinical audit of processes and outcomes; a process evaluation informing intervention feasibility, implementation, and behaviour change; and a cost-consequences analysis informing future economic evaluation. Performance data will be collected via audits of GP systems, hospital antenatal clinics and pregnancy outcomes. Following CAS theory, we will use repeated measurements to monitor intervention impact on pregnancy preparation markers at 4-monthly intervals over 18-months. We will use performance and feasibility data to optimise intervention effects iteratively. The target performance for the intervention is a 30% increase in the proportion of women meeting pre-pregnancy care criteria. Discussion The primary output will be development of an integrated programme of interventions to improve pregnancy preparation, pre-pregnancy care uptake, and reduce adverse pregnancy outcomes in women with T2DM. We will also develop an implementation plan to support the introduction of the interventions across the NHS. Trial registration ISRCTN47576591; February 8, 2022.

Aims The aim of the study was to examine the content and impact of interventions that have been used to increase the uptake of pre‐pregnancy care for women with type 2 diabetes, and their impact on maternal and fetal outcomes. Methods A systematic search of multiple databases was conducted in November 2021, and updated July 2022, to identify studies assessing interventions to enhance pre‐pregnancy care for women with type 2 diabetes. Over 10% of articles were screened by two reviewers at title and abstract phase, after which all selected full‐text articles were screened by two reviewers. Quality assessment was conducted using the Critical Appraisal Skills Programme checklist for cohort studies. Meta‐analysis was not possible due to study heterogeneity; therefore, narrative synthesis was conducted. Results Four eligible cohort studies were identified. The conclusions able to be drawn by this review were limited as women with type 2 diabetes (n = 800) were in the minority in all four studies (35%–40%) and none of the interventions were exclusively tailored for them. The uptake of pre‐pregnancy care was lower in women with type 2 diabetes (8%–10%) compared with other participant groups in the studies. Pregnancy preparation indicators generally improved among all groups exposed to pre‐pregnancy care, with varying impact on pregnancy outcomes. Conclusions This review demonstrates that previous interventions have had a limited impact on pre‐pregnancy care uptake in women with type 2 diabetes. Future studies should focus on tailored interventions for improving pre‐pregnancy care for women with type 2 diabetes, particularly those from ethnic minorities and living in poorer communities.