Association of the Serum Folate and Total Calcium and Magnesium Levels Before Ovarian Stimulation With Outcomes of Fresh In Vitro Fertilization Cycles in Normogonadotropic Women

Abstract

Background: Women of reproductive age are recommended to consume folic acid and other supplements before conception and during pregnancy. We aimed to investigate the association of the serum folate and total magnesium (Mg) and calcium (Ca) levels before ovarian stimulation with the outcomes of assisted reproductive technology (ART) in normogonadotropic women.

Methods: We used a subanalysis of data obtained from a multicentre, randomized prospective study (NCT03088137). A total of 110 normogonadotropic, non-advanced aged, non-obese women with tubal and/or male infertility factors were enrolled for the single fresh ovarian stimulation GnRH antagonist cycle. The main outcome measures were the total oocyte yield, mature oocytes, fertilization rate, biochemical, clinical pregnancy, and live birth. Multivariable generalized linear models adjusted for covariates were used with a Poisson distribution and the log link function for adjusted oocyte counts, and a binomial distribution and the log link function were used for adjusted clinical ART outcomes.

Results: The medians (interquartile range (IQR)) were as follows: baseline serum folate, 20.55 ng/ml (10.8, 32.9); Mg, 19.4 mg/L (18.7, 20.7); Ca, 94 mg/L (91.2, 96.4); and Ca/Mg ratio, 4.78 (4.55, 5.02). Women with higher serum folate concentrations (Q4≥33.0 ng/ml) had significantly lower total numbers of oocytes retrieved (adjusted mean (95% CI) 9.2 (7.6-11.3) vs 12.9 (10.9-15.4, p-trend=0.006)) and lower odds ratios (ORs) (95% CI) of 0.12 (0.02, 0.79) for clinical pregnancy and 0.10 (0.01, 0.70) for live birth compared with women in the lowest quartile (<10.8 ng/ml), all p-trend<0.001. Women in the highest Ca/Mg ratio quartile (≥5.02) had ORs (95% CI) of 6.58 (1.31, 33.04) for biochemical pregnancy, 4.85 (1.02, 23.08) for clinical pregnancy and 4.07 (0.83, 19.9) for the live birth rate compared with women in the lowest quartile (<4.55), all p-trend<0.001.

Conclusions: Using multivariable models, we suggested that a baseline elevated serum folate level (≥33.0 ng/ml) and a lower Ca/Mg ratio were associated with worse ART outcomes in normogonadotropic women. Our findings might be useful for choosing safe dosages of folate, calcium, magnesium and complex supplementation for both fertile women and women undergoing infertility treatment. Further preconception large-scale studies with known micro- and macronutrient statuses of both parents and serum folate, Ca, Mg, and hormone levels, are needed.

Keywords: ART; calcium; folate; folic acid; in vitro fertilization; magnesium; nutrition supplements; ovarian stimulation.

Conflict of interest statement

MP is employed by IVFarma LLC; the parental study NCT03088137 was financed by IVFarma LLC. DB served as a medical affairs consultant to Sanofi, Merck and Dr. Reddy’s. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2022 Polzikov, Blinov, Barakhoeva, Vovk, Fetisova, Ovchinnikova, Tischenko, Zorina, Yurasov, Ushakova and Sergeyev.

Figures

Figure 1

Flowchart of recruitment and follow up study subjects.

Figure 2

Time-line of biospecimen collection, clinical procedures and assessment of ART outcomes.

Figure 3

Distribution of baseline serum folate (A) and Ca/Mg ratio (B) concentrations in 110 women. Red dashed line is represent serum folate level 20 ng/ml considered “elevated” by WHO (27).

Figure 4

Adjusted mean oocyte counts by the quartiles of the serum folate level. (A) Total oocytes yield, adjustment for IVF/ICSI attempts (0; 1) and continuous BMI, baseline serum AMH and APTT, duration of stimulation and dose of FSH. (B) Mature oocytes, adjustment for continuous BMI, baseline serum AMH and APTT, duration of stimulation and dose of FSH. (C) Fertilized oocytes, adjustment for continuous BMI, baseline serum AMH and APTT, duration of stimulation and dose of FSH.

Figure 5

Predicted probability of occurring “no” (0) or “yes” (1) for clinical ART outcomes by the quartiles of the serum folate level. (A) Biochemical pregnancy, adjustment for continuous red blood cells, baseline serum FSH and antithrombin. (B) Clinical pregnancy, adjustment for continuous red blood cells and baseline serum FSH. (C) Live birth, adjustment for continuous red blood cells and baseline serum FSH.

Figure 6

Predicted probability of occurring “no” (0) or “yes” (1) for clinical ART outcomes by the quartiles of the serum Ca/Mg ratio. (A) Biochemical pregnancy, adjustment for continuous red blood cells, baseline serum FSH and antithrombin. (B) Clinical pregnancy, adjustment for continuous red blood cells and baseline serum FSH. (C) Live birth, adjustment for continuous red blood cells and baseline serum FSH.