A single nucleotide polymorphism of bone morphogenic protein-15 is not associated with ovarian reserve or response to ovarian stimulation

Effect of polymorphisms of MTHFR in controlled ovarian stimulation: a systematic review and meta-analysis

OBJECTIVE

Although several studies have reported a potential impact of methylenetetrahydrofolate reductase (MTHFR) polymorphisms on controlled ovarian stimulation (COS), the results remain controversial. The aim of the systematic review and meta-analysis was to evaluate the effect of MTHFR polymorphism on COS outcomes.

METHODS

PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials databases were searched up to December 2, 2020. COS clinical outcomes based on gene polymorphisms were included. Two reviewers independently extracted the data. The primary outcome was the number of oocytes retrieved. The secondary outcomes were the number of metaphase II (MII) oocytes, stimulation duration, basal follicle-stimulating hormone (FSH) level, FSH dosage, positive pregnancy test, ongoing pregnancy rate, clinical pregnancy rate, miscarriage rate, and live birth rate. Meta-analysis was performed using a fixed-effect model or random-effect model with Review Man 5.3.5. Mean difference (MD) with 95% confidence intervals (95%CIs) was calculated for continuous outcomes. The quality assessment of included studies was evaluated by using the Newcastle-Ottawa Scale.

RESULTS

Eleven studies were included in the systematic review, and seven studies with 2015 participants were included in the meta-analysis. Basal FSH level was significantly lower in CC homozygotes than TT homozygotes (four studies, 867 participants, MD - 0.54, 95%CI - 0.85 to - 0.23, P = 0.0006; I² = 0%) of MTHFR (rs1801133). FSH dose was significantly fewer in CC homozygotes compared with CT heterogeneous (three studies, 949 participants, MD - 75.78, 95%CI - 135.23 to - 16.33, P = 0.01; I² = 32%) or CT/TT model (three studies, 1097 participants, MD - 80.18, 95%CI - 135.54 to - 24.81, P = 0.005; I² = 42%). Differences in the oocytes retrieved and stimulation duration were insignificant. Gene variants on MTHFR (rs1801133) and MTHFR (rs1801131) were reported in ongoing pregnancy rate, clinical pregnancy rate, and live birth rate.

CONCLUSION

Studies to date indicate that polymorphisms of MTHFR could influence basal FSH level and FSH dose. The results could be useful to promote clinical practice on COS protocols. Further studies are needed to evaluate the clinical relevance of the multigene combination on COS.

An in silico model using prognostic genetic factors for ovarian response in controlled ovarian stimulation: A systematic review

PURPOSE

To study the use of in silica model to better understand and propose new markers of ovarian response to controlled ovarian stimulation before IVF.

METHODS

A systematic review and in silica model using bioinformatics. After the selection of 103 papers from a systematic review process, we performed a GRADE qualification of all included papers for evidence-based quality evaluation. We included 57 genes in the silica model using a functional protein network interaction. Moreover, the construction of protein-protein interaction network was done importing these results to Cytoscape. Therefore, a cluster analysis using MCODE was done, which was exported to a plugin BINGO to determine Gene Ontology. A p value of < 0.05 was considered significant, using a Bonferroni correction test.

RESULTS

In silica model was robust, presenting an ovulation-related gene network with 87 nodes (genes) and 348 edges (interactions between the genes). Related to the network centralities, the network has a betweenness mean value = 102.54; closeness mean = 0.007; and degree mean = 8.0. Moreover, the gene with a higher betweenness was PTPN1. Genes with the higher closeness were SRD5A1 and HSD17B3, and the gene with the lowest closeness was GDF9. Finally, the gene with a higher degree value was UBB; this gene participates in the regulation of TP53 activity pathway.

CONCLUSIONS

This systematic review demonstrated that we cannot use any genetic marker before controlled ovarian stimulation for IVF. Moreover, in silica model is a useful tool for understanding and finding new markers for an IVF individualization.

PROSPERO

CRD42020197185.

Alterations in follicular fluid BMP-15 RNA expression in women undergoing controlled ovarian hyperstimulation

Background/aim

Bone morphogenetic protein-15 (BMP-15) is one of the maturation indicators of the ovarian follicular pool. The aim of this study was to investigate the possible difference of follicular fluid (FF) BMP-15 RNA expression among low, normal, and high responder women attending controlled ovarian hyperstimulation-intracytoplasmic sperm injection (COH-ICSI) cycles.

Materials and methods

This cross-sectional study was conducted with 75 FFs of COH-ICSI cycles performed at the IVF Unit of University Hospital. Twenty FF from low response (group 1), 27 FF from normal response (group 2), and 28 FF from high response (group 3) were recruited for the study between September 2014 and February 2015. Cycle parameters were collected from patient files. FF BMP-15 RNA expression was evaluated with real-time polymerase chain reaction analysis. Statistical analysis was done with SPSS 16.0 version (SPSS Chicago, IL, USA).

Results

The mean age, infertility duration, and body mass index (BMI) of patients were 31.1 ± 4.4 years, 7.4 ± 4.5 years, and 25.6 ± 4.1 kg/m², respectively. There was no significant difference among groups for age, infertility duration, and BMI. There was no significant difference among groups for fertilization rate, implantation rate, pregnancy rate, and live birth rate. Among the 3 groups, FF BMP-15 RNA overexpression and lower expression rates were not significantly different. In all groups, overexpression showed dominance. The pregnancy rate was 45% among women with lower expression and the pregnancy rate among women with overexpression was 26% (P = 0.02). BMP-15 overexpression showed impact on becoming pregnant (OR = 3.7, 95% CI = 1.245–11.299, P = 0.019).

Conclusion

In this study, there was no significant difference in FF BMP-15 RNA expression levels among low, normal, and high responder women. However, overexpression of FF BMP-15 RNA showed a negative impact on pregnancy rates of women who attended COH-ICSI cycles.

Association of a promoter polymorphism in FSHR with ovarian reserve and response to ovarian stimulation in women undergoing assisted reproductive treatment

Previous studies have suggested an association between a variant in the promoter region of the FSHR gene and diminished response to controlled ovarian hyperstimulation (COH) in women undergoing assisted reproduction. FSHR -29G>A was genotyped in 559 women undergoing their first cycle of COH for IVF/intracytoplasmic sperm injection (ICSI) using TaqMan allelic discrimination assay. Correlation and regression analysis was performed to assess the relationship between FSHR promoter genotypes and markers of ovarian reserve and measures of response to COH, including the number of oocytes retrieved, gonadotrophin dose used and the live-birth rate. There were no statistically significant differences between the genotype frequencies and the markers of ovarian reserve or the early measures of response to COH. However, the live-birth rate was higher for women carrying the variant A allele (odds ratio [OR] 1.37; 95% confidence interval [CI] 1.02-1.84 per allele). This relationship did not reach statistical significance after adjustment for the number of embryos transferred (OR 1.33; 95% CI 0.98-1.83 per allele). Results from this study do not provide evidence that the FSHR -29G>A variant can be used in the individualization of the treatment protocol for women undergoing IVF/ICSI.

AMH type II receptor and AMH gene polymorphisms are not associated with ovarian reserve, response, or outcomes in ovarian stimulation

Purpose

Genetic variation may influence women’s response to ovarian stimulation therapy. The purpose of this study was to investigate any effects of genetic variants in the anti-Müllerian hormone (AMH) and AMH type II receptor genes on ovarian response/treatment outcomes and on current markers of ovarian reserve in individuals undergoing in vitro fertilisation (IVF) treatment.

Methods

In this prospective observational study, we genotyped the AMH c.146G>T, p.(Ile49Ser) and AMHR2 -482A>G variants in 603 unrelated women undergoing their first cycle of controlled ovarian stimulation for IVF and ICSI (intracytoplasmic sperm injection) using gonadotrophins at a tertiary referral centre for reproductive medicine. Pelvic ultrasound and blood hormone levels were taken on days 2–3 of the cycle. Genotypes were determined using TaqMan allelic discrimination assay. Regression analysis was performed to assess the relationship between the genotypes and the ovarian reserve markers (FSH, AMH, antral follicle count) and the early outcomes of response (number of oocytes retrieved and gonadotropin dose) as well as the treatment outcome (live birth).

Results

There were no significant associations between the variants AMH c.146G>T and AMHR2 -482A>G with ovarian response in terms of number of oocytes retrieved (p = 0.08 and p = 0.64, respectively), live births (p = 0.28 and p = 0.52) and/or markers of ovarian reserve.

Conclusions

Genotyping of the AMH c.146G>T and AMHR2 -482A>G polymorphisms does not provide additional useful information as a predictor of ovarian reserve or ovarian response and treatment outcomes.