Does Vitamin B12 Influence Clinical Pregnancy Outcome in the follicular-phase GnRH agonist protocol?

Purpose To investigate whether vitamin B12 levels affect IVF-ET pregnancy outcomes. Design Single-center, retrospective, observational study. Patients From November 2018 to December 2019, patients who received IVF-assisted pregnancy treatment were analyzed. Main outcome measures The primary outcome was the clinical pregnancy rate (CPR). RESULTS After adjusting for Age, BMI, AMH, cleavage-stage embryos/blastocysts, and the number of transferred embryos, when the vitamin B12 value was ≤353.2 pg/ml, for every 10 pg/ml increase in the vitamin B12 value, the clinical pregnancy rate increased by 5% (OR=1.05, 95% CI=1.00, 1.09, P=0.0304). CONCLUSION Serum vitamin B12 levels may be an important factor related to the clinical pregnancy rate for women who undergo IVF-ET with the follicular-phase GnRH agonist protocol.