Hybrid closed loop insulin therapy versus standard therapy in pregnant women with type 1 diabetes: A systematic review and meta-analysis of randomized controlled trials

Objective: We aimed to explore the efficacy and safety of hybrid closed loop (HCL) systems compared to standard care (SC) in pregnant women with Type 1 Diabetes Mellitus (T1DM), pooling results from randomized controlled trials (RCTs). Data sources: We searched through multiple databases like PubMed, Cochrane, Embase, Web of Science, and Clinicaltrials.gov etc. from inception to September 2024 and found six relevant studies after screening. Study eligibility criteria: We included studies that were (1) RCTs; with patient population (2) pregnant patients with type 1 diabetes; intervention group receiving (3) HCL and control group receiving (4) SC; while reporting (5) outcomes of interest (endpoints). We pooled results pertaining to primary outcomes; time in range (TIR), nocturnal time in range (nTIR), and HbA1c; and relevant secondary outcomes. Study appraisal and synthesis methods: We used Rob 2: A revised Cochrane risk-of-bias tool for randomized trials for quality assessment of the included RCTs. We employed the DerSimonian-Laird random effects model using review manager 5.4 to analyze the pooled estimates and reported results as risk ratio; for dichotomous outcomes; or mean difference; for continuous outcomes. Results: Five RCTs (n = 274) with disparate populations were narrowed down for analysis. Pooled estimates for TIR (MD 4.95 %;−0.56 to 10.49)and HbA1c% (MD 0.09; −0.44 to 0.63) were statistically non-significant, while estimates for nTIR (MD 11.16 %; 7.15 to 15.15), % time < 63 mg/dL (MD –0.78; −1.36 to −0.20), % of time < 54 mg/dL (MD –0.22; −0.40 to −0.03), low blood glucose index (LBGI) (MD –0.30; −0.54 to −0.06), and glucose standard deviation (MD −3.05; −6.06 to −0.04) favored HCL over SC. No significant between-group differences were found in other secondary outcomes: % of time >140 mg/dL, % of time >180 mg/dL, mean glucose level, rate of serious adverse events, cesarian delivery, and severe hypoglycemia. Conclusions: HCL systems can improve glycemic control in pregnant women with T1DM with a tolerable adverse event profile, however more research is needed to draw a definitive conclusion.