The impact of Duostim protocol on pregnancy outcomes in infertile patients: A meta-analysis comparing single and double conventional stimulation cycles.

Background: The DuoStim protocol has been proposed as an alternative to conventional single and double stimulation cycles in the treatment of infertility. However, its efficacy in improving pregnancy outcomes remains uncertain.

Objective: To systematically evaluate the impact of the DuoStim protocol on pregnancy outcomes in infertile patients by comparing it with single and double conventional stimulation cycles.

Methods: An online systematic search was conducted using PubMed, Cochrane Library, and EMBASE databases, covering the period from their inception to March 2024. Randomized controlled trials (RCTs) comparing the DuoStim protocol with single and double conventional stimulation cycles in infertile patients were identified. Data were extracted by two independent investigators who screened the literature and assessed the quality of the studies. Meta-analysis was performed using RevMan 5.4 software.

Results: A total of six RCTs involving 414 infertile patients were included. The DuoStim protocol significantly increased the total number of oocytes compared to single and double conventional stimulation (MD =  - 1.47; 95% CI, - 2.12 to - 0.82; P < 0.00001). There were no statistically significant differences in the number of MII oocytes, total embryos, pregnancy rate, and live birth rate. Subgroup Analysis: compared to single stimulation, the DuoStim protocol significantly increased the number of MII oocytes (MD = 1.71; 95% CI, 0.77 to 2.66; P = 0.0004) and total embryos (MD = 1.34; 95% CI, 0.61 to 2.08; P = 0.0003). There were no significant differences in pregnancy rate and live birth rate. Secondary outcomes showed the effect of the DuoStim protocol in patients undergoing preimplantation genetic testing for aneuploidies (PGT-A). The time to obtain euploid blastocysts was significantly reduced in the DuoStim group compared to the control group (23.3 ± 2.8 days vs. 44.1 ± 2.0 days; P < 0.001).

Conclusions: The DuoStim protocol shows a significant advantage in increasing the total number of oocytes, MII oocytes, and embryos compared to single stimulation. However, it does not significantly improve pregnancy and live birth rates. The protocol also shortens the time to obtain euploid blastocysts in patients undergoing PGT-A, indicating potential benefits for specific patient groups. Further research is needed to confirm these findings and evaluate long-term outcomes. Thus, the quality of evidence should be considered moderate, warranting cautious interpretation of the results.