Skip to main content

Advertisement

Table 1 Characteristic of studies included in our meta-analysis

From: Whether vitamin D was associated with clinical outcome after IVF/ICSI: a systematic review and meta-analysis

Studies Country Study design Protocol Sample size The time of sample collection Vd grouping criteria Outcome measures Main result Main confounding factors
Anifandis et al. 2010 [8] Greece Retrospective cohort study Short agonist protocol IVF/ICIS 101 During oocyte retrieval < 20 ng/ml; 20.1-30 ng/ml; > 30 ng/ml Clinical pregnancy rate (CPR) Higher FF levels of 25(OH)D are associated with lower FF glucose levels and with lower CPR Age BMI Oocytes retrieved (n)
Rudick et al. 2012 [10] USA Retrospective cohort study Long agonist Flare-up GnRH-ant IVF/ICSI 188 After hCG administration < 20 ng/ml; 20-30 ng/ml; > 30 ng/ml ou Opposite relation between 25(OH)D levels and IVF outcomes by race Age BMI Embryos transferred (n, quality) Poor ovarian reserve
Firouzabadi et al. 2013 [14] Iran Prospective cohort study Long GnRH-a protocol IVF 221 On the day of ovum pick-up < 10 ng/ml 10-29 ng/ml 30-100 ng/ml CPR No significant association between FF or serum levels of 25(OH)D and CPR None
Garbedian et al. 2013 [9] USA Prospective cohort study Long GnRH-a Flare-up GnRH-ant IVF 162 Before oocyte retrieval < 75 nmol/l ≥75 nmol/l CPR High vitamin D level was related to higher CPR Age BMI Day 5[v. day3] embryo transfer
Fabris et al. 2014 [17] Spain Retrospective cohort study Egg donation recipients 267 After 2 weeks of HRT < 20 ng/ml; 20-30 ng/ml; > 30 ng/ml CPR; Ongoing pregnancy rate Low vitamin D level was not related to decreased CPR with egg donation. BMI
Paffoni et al. 2014 [12] Italy Prospective cohort study Long GnRH-a Flare-up GnRH-ant IVF 335 Prior to to initiation of COH < 20 ng/ml; ≥20 ng/ml CPR; Implantation rate High vitamin D level was related to higher CPR Race BMI
Polyzos et al. 2014 [13] Belgium Retrospective cohort study Irrespective of the protocol Single, blastocyst IVF/ICSI 368 On the day of hCG administration < 20 ng/ml; ≥20 ng/ml Chemical PR CPR; Live birth rate (LBR) Low vitamin D level was related to lower clinical pregnancy rate and live birth rate Season of embryo transfer
Rudick et al. 2014 [11] USA Retrospective cohort study Egg donation recipients 99 At the time of down-regulation < 20 ng/ml; 20-30 ng/ml; > 30 ng/ml CPR; LBR Higher 25(OH)D levels associated with higher CPR and LBR Recipient age Recipient BMI Embryos transferred(n, quality)
Franasiak et al. 2015 [18] Canada Retrospective cohort study Long GnRH-a Flare-up GnRH-ant FET/ICSI 517 On the day of ovulation trigger < 20 ng/ml; 20-30 ng/ml; > 30 ng/ml CPR Ongoing PR Vitamin D had no relationship with IVF outcomes Age No. of embryo transferred Race