Imprinting disorders in children conceived with assisted reproductive technology in Sweden.

OBJECTIVE: To assess whether the use of assisted reproductive technology (ART) therapy for conception is associated with imprinting disorders in children and the impact of parental factors related to infertility. DESIGN: A nationwide register-based cohort study. SETTING: Swedish national registers and nationwide quality IVF register. PATIENT(S): All liveborn singletons in Sweden (N = 2,084,127) between 1997 and 2017 with follow-up to December 31, 2018. INTERVENTION(S): The use of specific methods implemented in ART. MAIN OUTCOME MEASURE(S): The International Classification of Diseases version 10 was used to identify three distinct imprinting disorder groups: Beckwith-Wiedemann syndrome (BWS), Prader-Willi syndrome (PWS), and Silver-Russell syndrome (SRS), as well as central precocious puberty. The Cox model combined with inverse probability treatment weights was used to estimate the weighted hazard ratio (wHR) with a 95% confidence interval (CI), accounting for multiple confounders. RESULT(S): A total of 1,044 children were diagnosed with the disorders of interest, and 52 of them were conceived using ART therapy. The overall risk of being diagnosed with any of the studied imprinting disorders was elevated in children conceived using ART therapy compared with all other children (HR, 1.84; 95% CI, 1.38-2.45). After adjusting for parental background factors, the association was partially attenuated (wHR, 1.50; 95% CI, 0.97-2.32), but remained in the weighted comparison restricted to children of couples with known infertility (wHR, 1.52; 95% CI, 1.05-2.21). For the specific diagnoses of PWS/SRS, and BWS compared with children of couples with known infertility, children conceived with ART therapy showed a small excess risk, which could not be distinguished from the null (wHR, 1.56; 95% CI, 0.93-2.62 and 1.80; 95% CI, 0.99-3.28, respectively). Further subgroup analysis showed that the combined use of intracytoplasmic sperm injection and cryopreserved embryos was associated with a higher risk of both PWS/SRS (wHR, 4.60; 95% CI, 1.72-12.28) and BWS (wHR, 6.69; 95% CI, 2.09-21.45). The number of central precocious puberty cases in children conceived using ART therapy was too small (N = 3) to make any meaningful inference. CONCLUSION(S): The combined use of intracytoplasmic sperm injection and cryopreserved embryos was associated with small elevated risks of PWS/SRS, and BWS in children, independent of parental factors related to infertility.

Update on the Epigenomic Implication of Embryo Cryopreservation Methods Applied in Assisted Reproductive Technologies With Potential Long-Term Health Effects.

Cryopreservation of embryos has become an efficient method in Assisted Reproductive Technologies (ART) and these methods are currently performed at nearly all fertility centers around the globe. Cryopreservation of supernumerary embryos has contributed to an increase in cumulative pregnancy rates and as a consequence, an increasing number of children are being born through these techniques worldwide. However, long-term follow-up studies of children born through ART are scarce, and concerns about the long-term health effects on individuals conceived through ART have been raised. The relevant genomic transformations that occur at the time cryopreservation is usually applied to embryos may have potential epigenetic risks. With advances in multi-omic single cell technologies, new ways to assess the (epi)genomic status during early embryo development have now become feasible. These novel strategies could provide a revolutionary opportunity to understand the actual impact of ART, but also may help future developments aiming at increase both their efficiency and safety. Here we outline insights in current knowledge and research on the impact of cryopreservation on embryos, the possible consequences at epigenetic level and how emerging new high-throughput technologies can be used for their assessment.

Sperm count and motility are quantitatively affected by functional polymorphisms of HTR2A, MAOA and SLC18A.

Spermatozoa and neurones share similar membrane characteristics and features. Associations of multiple polymorphisms traditionally related to neurotransmission were investigated. Infertile men were grouped into controls with normospermia (n = 182) and idiopathic infertile men with asthenozoospermia (n = 103), and analysed as a case-control study and as a quantitative association of each genotype. Ten neurotransmission-associated genetic variants were mapped by SNP analysis using quantitative polymerase chain reaction with TaqMan probes. Men with HTR2A rs6313 had a higher risk of asthenozoospermia (OR = 2.14; P = 0.04). MAOA rs3788862 G carriers displayed an increased risk of asthenozoospermia (OR = 2.29; P = 0.02). The SLC18A1 rs1390938 G allele was more frequent among such cases (0.75 versus 0.87; P < 0.01 and P < 0.01 for Armitage trend test); for SLC18A1 rs2270641 P = 0.02 (case-control frequency) and P = 0.01 (Armitage trend test). MAOA rs3788862 was correlated with sperm motility (Spearman ρ = 0.14; P = 0.02); SLC18A1 rs1390938 was correlated with sperm count and motility (Spearman ρ = 0.20; P < 0.01). Gene polymorphisms of HTR2A, MAOA and SLC18A1, related to neurotransmission, are individually associated with asthenozoospermia through variation in sperm count and motility, without detectable allelic or genotype interaction.

Fetal alpha 5-reductase Val89Leu mutation is associated with late miscarriage.

The present study was undertaken to determine the role of different polymorphisms affecting the testosterone/oestrogen pathway in miscarriage. Alpha 5-reductase (SRD5A2) rs523349 and rs9282858, cytochrome P450 aromatase (CYP19A1) rs4646, rs10046 and rs2236722 and oestrogen receptor (ESR1) rs9340799, rs2234693 and rs6932902 polymorphisms were selected. The case group consisted of 94 samples of formalin-fixed and paraffin-embedded fetal tissue from a miscarriage at ≤24 weeks. The control group comprised a population of 331 young healthy subjects. Only those single nucleotide polymorphisms (SNPs) fitting the Hardy-Weinberg equilibrium (n = 4) and euploid miscarriage samples (n = 67) were included for downstream analysis. Interestingly, SRD5A2 rs523349 (Val89Leu) was significantly associated with the risk of undergoing miscarriage after Bonferroni correction (odds ratio = 11.245, P < 2.2 × 10-9). Moreover, when Mantel-Cox regression analysis was performed, we observed that the effect was significantly constrained to the second trimester (P = 0.024, log rank). These results are compatible with an imbalance of testosterone/dihydrotestosterone, associated with a higher risk of miscarriage, especially in late pregnancy.