Does vitamin B12 influence clinical pregnancy outcome in the follicular-phase GnRH agonist protocol?

2025-10-21
BMC pregnancy and childbirth 25(1)
- Xiaoning Wang
- Kui Fu
- Ying Zhang
- Shengfang Jiang
- Changjun Zhang

PubMed: 41120970
DOI: 10.1186/s12884-025-08250-3

Study Design

Type: Observational
Population: women undergoing IVF-ET with the follicular-phase GnRH agonist protocol
Methods: Single-center, retrospective, observational study

Purpose

To investigate whether vitamin B12 levels affect IVF-ET pregnancy outcomes.

Design

Single-center, retrospective, observational study.

Design

Single-center, retrospective, observational study.

Main outcome measures

The primary outcome was the clinical pregnancy rate (CPR).

Results

After adjusting for Age, BMI, AMH, number of oocytes retrieved, cleavage-stage embryos/blastocysts, and the number of transferred embryos, when the vitamin B12 value was ≤358.7 pg/ml, for every 10 pg/ml increase in the vitamin B12 value, the clinical pregnancy rate increased by 4% (OR=1.04, 95% CI=1.00, 1.08, P=0.03).

Conclusion

Within a specific range (≤358.7 pg/mL), serum vitamin B12 levels may modestly contribute to improved clinical pregnancy rates in women undergoing IVF-ET with the follicular-phase GnRH agonist protocol, though further validation is required to confirm its clinical significance.

Trial registration

None.

Research Insights

Vitamin B12→Increased Clinical Pregnancy Rate
when the vitamin B12 value was ≤358.7 pg/ml, for every 10 pg/ml increase in the vitamin B12 value, the clinical pregnancy rate increased by 4% (OR=1.04, 95% CI=1.00, 1.08, P=0.03).
Effect
Beneficial
Effect size
Small