Associations of fertility parameters with fatty acids and DNA methylation in Mexican women undergoing in vitro fertilization

BACKGROUND

Fatty acids (FA) likely affect human fertility at multiple levels, as deviations from physiological FA profiles are obesogenic, and FA can modify DNA methylation (DNAm). Yet, the interplay of follicular fluid (FF) and serum FA with BMI and percentage body fat (PBF) in human fertility is not completely understood. Also, associations of DNAm with fertility are largely unexplored.

METHODS

Reproductive parameters ranging from retrieved oocyte number to infant birth weight, were recorded in Mexican women undergoing in vitro fertilization (n = 88). Multiple regression analysis sought BMI-adjusted and age-adjusted associations. Receiver operating characteristic analysis tested for discrimination between outcomes.

RESULTS

Associations of FF and serum FA were markedly distinct. While various FF FA (C16:1, C18:0, C20:2, C20:3, arachidonic acid) were significantly and inversely associated only with retrieved oocyte number, selected serum FA were associated with a broad range of pre-fertilization and post-fertilization parameters. Associations of BMI and FF FA were complex, as arachidonic acid was inversely associated with both BMI and retrieved oocyte number, while oleic acid (OA) was directly associated with BMI and PBF. Ultrasound-assessed clinical pregnancy outcome (CP) was directly associated with serum OA but inversely with its trans isomer elaidic acid (EA) and with BMI. Compounded BMI, serum EA and OA discriminated CP well (AUC = 0.74). Whole blood DNA methylation was significantly associated with and a moderate predictor (AUC = 0.66) of percent fertilized oocytes.

CONCLUSIONS

Overall FF FA pool composition rather than FA identity may impact oocyte production and cellular memory of FF FA is lost as the oocyte exits the follicular environment. The contrasting associations of BMI, FF OA and arachidonic acid suggest that the control of oocyte homeostasis by FF FA is uncoupled from BMI. Further studies are warranted to assess the potential of compounding BMI with serum EA and OA to predict CP.

An Extremely Low-Frequency Vortex Magnetic Field Modifies Protein Expression, Rearranges the Cytoskeleton, and Induces Apoptosis of a Human Neuroblastoma Cell Line

Homogeneous extremely low-frequency electromagnetic fields (ELF-EMFs) alter biological phenomena, including the cell phenotype and proliferation rate. Heterogenous vortex magnetic fields (VMFs), a new approach of exposure to magnetic fields, induce systematic movements on charged biomolecules from target cells; however, the effect of VMFs on living systems remains uncertain. Here, we designed, constructed, and characterized an ELF-VMF-modified Rodin's coil to expose SH-SY5Y cells. Samples were analyzed by performing 2D-differential-gel electrophoresis, identified by MALDI-TOF/TOF, validated by western blotting, and characterized by confocal microscopy. A total of 106 protein spots were differentially expressed; 40 spots were downregulated and 66 were upregulated in the exposed cell proteome, compared to the control cell proteome. The identified spots are associated with cytoskeleton and cell viability proteins, and according to the protein-protein interaction network, a significant interaction among them was found. Our data revealed a decrease in cell survival associated with apoptotic cells without effects on the cell cycle, as well as evident changes in the cytoskeleton. We demonstrated that ELF-VMFs, at a specific frequency and exposure time, alter the cell proteome and structurally affect the target cells. This is the first report showing that VMF application might be a versatile system for testing different hypotheses in living systems, using appropriate exposure parameters.© 2022 Bioelectromagnetics Society.

Oocyte maturation arrest produced by TUBB8 mutations: impact of genetic disorders in infertility treatment

Oocyte maturation defect is a challenging situation in the management of infertility, the etiology may be related to endocrine causes, protocols used in ovarian stimulation, oocyte intrinsic defects or procedures in embryology laboratory. We report three Mexican females in treatment for primary infertility with non-mature oocytes after ovary stimulation and oocyte capture in whom a genetic diagnosis of TUBB8-oocyte maturation defect was revealed by exome sequencing. Two couples achieved pregnancies though oocyte donation after establishing the genetic etiology. Our results expand the role of TUBB8-disorders in patients of non-Asian ethnicity. Oocyte maturation defects of monogenic origin are a growing group of disorders that endocrinologists and reproductive medicine specialists should be aware in order to provide referral to genetics for establish a correct and opportune diagnosis.

Natural-cycle in vitro fertilization (IVF) combined with in vitro maturation in infertile patients with polycystic ovarian syndrome (PCOS) requiring IVF

OBJECTIVE

In this study, we report an experience of 59 natural-cycle IVF combined with in vitro oocyte maturation (IVF/M) cycles in patients with PCOS requiring IVF recruited based on limitations to afford a conventional IVF treatment in a 9-years period. Results of IVF/M were compared with 164 cycles of IVF in PCOS patients.

MATERIAL AND METHODS

In IVF/M cycles only hCG priming was used before oocyte recovery, with in vitro maturation of immature oocytes in a commercial medium. In conventional IVF group, recombinant FSH (rFSH) and GnRH agonist/antagonist for ovarian stimulation were used. In both groups, fertilization was achieved by intracytoplasmic sperm injection (ICSI) of mature oocytes and fresh embryos transferred at day 2 or day 3.

RESULTS

In all IVF/M cycles oocytes and transferable quality embryos were obtained, only in 6 IVF/M cycles mature oocytes were obtained at oocyte capture day. Clinical pregnancy rate per cycle was 39.0% vs 53.6% (p = 0.0682) and delivery rate per cycle was 30.5% vs 42.6% (p = 0.1209) in IVF/M and conventional IVF respectively. Patients with ovarian hyperstimulation syndrome (OHSS) were 0% in IVF/M vs 6.7% in conventional IVF (p = 0.0399).

CONCLUSION

Our experience in a private clinic in Mexico suggests that IVF/M can be a useful initial strategy to treat PCOS patients requiring IVF with comparable delivery rates to conventional IVF and a decreased risk of ovary hyperstimulation. IVF/M may be indicated to patients with limited resources paying without insurance for their infertility treatment.

[Polarized light microscopy for evaluation of oocytes as a prognostic factor in the evolution of a cycle in assisted reproduction]

BACKGROUND

Identification of the best embryos to transfer is a key element for success in assisted reproduction. In the last decade, several morphological criteria of oocytes and embryos were evaluated with regard to their potential for predicting embryo viability. The introduction of polarization light microscopy systems has allowed the visualization of the meiotic spindle and the different layers of the zona pellucida in human oocytes on the basis of birefringence in a non-destructive way. Conflicting results have been reported regarding the predictive value in ICSI cycles.

OBJECTIVE

To assess the predictive ability of meiotic spindle and zona pellucida of human oocytes to implant by polarized microscopy in ICSI cycles.

MATERIAL AND METHODS

Prospective and observational clinical study. 903 oocytes from 94 ICSI cycles were analyzed with polarized microscopy. Meiotic spindle visualization and zona pellucida birefringence values by polarized microscopy were correlated with ICSI cycles results.

RESULTS

Meiotic spindle visualization and birefringence values of zona pellucida decreased in a direct basis with increasing age. In patients aged over the 35 years, the percentage of a visible spindle and mean zona pellucida birefringence was lower than in younger patients. Fertilization rate were higher in oocytes with visible meiotic spindle (81.3% vs. 64%; p < 0.0001), as well as embryo quality (47.4% vs. 39%; p=0.01). Fertilization rate was higher in oocytes with positive values of birefringence (77.5 % vs. 68.5% p=0.005) with similar embryo quality. Conception cycles showed oocytes with higher mean value of zona birefringence and visible spindle vs. no-conception cycles (p<0.05).

CONCLUSIONS

Polarized light microscopy improves oocyte selection, which significantly impacts in the development of embryos with greater implantation potential. The use of polarized light microscopy with sperm selection methods, blastocyst culture and deferred embryo transfers will contribute to transfer fewer embryos without diminishing rates of live birth and single embryo transfer will be more feasible.

[Impact of laser-assisted hatching (quarter technique) in poor prognosis patients]

BACKGROUND

Poor implantation rates continue to be the determinant factor for results in assisted reproductive techniques; many factors are thought to be involved including embryo quality, endometrial receptivity and embryo transfer. Assisted hatching has been proposed as a technique to improve implantation rates in selected groups of patients, especially with poor prognosis.

OBJECTIVE

To evaluate the impact of the laser assisted hatching performed with quarter technique in patients with poor prognosis.

MATERIAL AND METHODS

Prospective, controlled and randomized clinical study. The study group included patients with poor prognosis: maternal age ≥ 38 years, basal FSH ≥ 12.0 mUl/mL, two or more previous FIV/ ICSI failures. The control group don't received neither assisted reproductive techniques.

RESULTS

We registered 303 cycles: n=1 54 in study group (laser assisted hatching) and n = 149 in control group. Clinical pregnancy (40.1 vs 19.7%) and implantation (17.5 vs 8.3%) rates were significant higher in laser assisted hatching group, there were not significant differences between multiple pregnancy (13.11 vs 10%) and miscarriage (14.7 vs 17.2) rates.

CONCLUSION

Laser assisted hatching with quarter technique improves pregnancy and implantation rates in poor prognosis patients.

Y chromosome microdeletions in Mexican males of couples with idiopathic recurrent pregnancy loss

AIM

To analyze the presence of Y chromosome microdeletions in males of Mexican couples with idiopathic recurrent pregnancy losses (RPL).

METHODS

Seventy-one males from couples with RPL and 66 fertile males as controls were studied. DNA was isolated from peripheral lymphocytes and used to run multiplex polymerase chain reactions. Regions AZFa (sY84, sY86), AZFb (sY127, sY134) and AZFc (sY254, sY255) of the Y chromosome were analyzed according to valid guidelines recommended by the European Academy of Andrology and the European Molecular Genetics Quality Network. Also, the sequence tagged sites (STSs): DYS262 (sY67), DYS220 (sY129), DYF85S1 (sY150), DYF86S1 (sY152) and DYF87S1 (sY153) were included in order to analyze STSs previously reported as deleted. A power analysis to support our simple size was performed.

RESULTS

Results show an absence of Y chromosome microdeletions in males of couples with RPL and controls with an acceptable statistical power.

CONCLUSION

The study did not show an association of recurrent pregnancy loss and Y chromosome microdeletions in Mexican male partners. Based on the results, the study of Y chromosome microdeletions in couples with RPL is not considered clinically relevant.