Association of blood vitamin D levels with the outcomes of assisted reproductive technology programs

Objective. To investigate the effect of blood vitamin D levels on embryo implantation and efficiency of assisted reproductive technology (ART) programs. Subjects and methods. The investigation enrolled 201 patients who met the inclusion criteria. The women were divided into 2 groups according to treatment options: A) 201 patients who had been treated by in vitro fertilization/ intracytoplasmic sperm injection (IVF/ICSI) and superovulation and embryo transfer in this cycle; B) 111 patients in whom pregnancy had not occurred in the stimulated cycle and they continued to be treated with cryopreserved/thawed embryo transfer. Serum 25-hydroxyvitamin D (25-OH D) levels were determined in all the patients. According to vitamin D levels, the women were divided into 3 subgroups: 1) blood vitamin D deficiency (< 10 ng/ml); 2) inadequate blood levels of vitamin D (10-29 ng/ml); 3) its normal blood levels (30-100 ng/ml). Results. In stimulated cycles, embryo implantation and clinical pregnancy occurred in 10 (35.7%) patients in Subgroup 1 with 25-OH D deficiency, in 41 (29.7%) in Subgroup 2, and in 9 (25.7%) in Subgroup 3. In natural-cycle cryopreserved-thawed embryo transfer, pregnancy occurred in 5 (38.5%) patients in Subgroup 1, in 40 (53.3%) in Subgroup 2, and in 17 (73.9%) in Subgroup 3. In unstimulated-cycle cryopreserved-thawed embryo transfer, there was a direct correlation of normal blood vitamin D levels with the higher efficiency in ART programs, i.e. the highest clinical pregnancy rate was observed in the normal vitamin D level group. Conclusion. In unstimulated-cycle cryopreserved-thawed embryo transfer, the normal blood vitamin D level was associated with successful implantation and higher clinical pregnancy rates.

infertility, vitamin D, in vitro fertilization, stimulated cycle, cryopreserved-thawed embryos