Effects of immediate versus delayed frozen embryo transfer in high responder patients undergoing freeze-all cycles

Background Frozen embryo transfer (FET) can greatly improve the pregnancy outcomes for high responder patients. However, it is not known whether the timing of FET is a risk factor on pregnancy outcomes in high responder patients undergoing freeze-all cycles. Methods A retrospective cohort study to compare the pregnancy outcomes of the immediate and delayed FET groups in high responder patients undergoing freeze-all cycles. The two groups were defined as that FET took place either within the first menstrual cycle following oocyte retrieval or afterwards. Propensity score matching was used to make the potential risk factors of the two groups comparable. Multivariable regression analysis was used to study the effect of the timing of FET on pregnancy outcomes in the entire cohort and propensity score-matched cohort, even in different controlled ovarian hyperstimulation protocol cohorts as subgroup analysis. Results We obtained 1130 patients in immediate FET group and 998 patients in delayed FET group, and the average age of the two groups were 30.30 and 30.63. We showed that the immediate FET group were equivalent to delayed FET group in the entire cohort [clinical pregnancy rate (CPR), 61.0% versus 63.4%, adjusted odd ratio (OR), 0.939, 95% confidence interval (CI), 0.781–1.129; spontaneous abortion rate (SAR), 10.1% versus 12.6%, adjusted OR, 0.831, 95% Cl (0.628–1.098); live birth rate (LBR), 49.9% versus 49.2%, adjusted OR, 1.056, 95% Cl (0.883–1.263)]. The same results were obtained by χ2 test in the propensity score-matched cohort (CPR, 60.5% versus 63.5%; SAR, 11.6% versus 12.3%; LBR, 48% versus 49.3%) (P > 0.05). Subgroup analysis indicated that pregnancy outcomes of immediate FET were no difference to delayed FET in gonadotropin-releasing hormone agonist (GnRH-a) protocol (P > 0.05). The SAR of the immediate FET group were lower than that of the delayed FET group in GnRH antagonist protocol (adjusted OR, 0.645, 95% CI, 0.430–0.966) (P < 0.05), no differences were observed in CPR and LBR (P > 0.05). Conclusions The pregnancy outcomes of immediate FET were no difference to delayed FET in high responder population undergoing freeze-all cycles.

Myokine Responses to Exercise in a Rat Model of Low/High Adaptive Potential

IntroductionAssuming myokines underlie some of the health benefits of exercise, we hypothesised that ‘high responder trainer’ (HRT) rats would exhibit distinct myokine profiles to ‘low responder trainers’ (LRT), reflecting distinct health and adaptive traits.MethodsBlood was collected from LRT and HRT (N=8) rats at baseline (BL), immediately (0h), 1h, and 3h after running; repeated after 3-wks training. Myokines were analysed by ELISA (i.e. BDNF/Fractalkine/SPARC/Irisin/FGF21/Musclin/IL-6).ResultsAt baseline, Musclin (LRT: 84 ± 24 vs HRT: 26 ± 3 pg/ml, P=0.05) and FGF21 (LRT: 133 ± 34 vs HRT: 63.5 ± 13 pg/ml, P=0.08) were higher in LRT than HRT. Training increased Musclin in HRT (26 ± 3 to 54 ± 9 pg/ml, P&lt;0.05) and decreased FGF21 in LRT (133 ± 34 to 60 ± 28 pg/ml, P&lt;0.05). Training increased SPARC (LRT: 0.8 ± 0.1 to 2.1 ± 0.6 ng/ml, P&lt;0.05; HRT: 0.7 ± 0.06 to 1.8 ± 0.3 ng/ml, P=0.06) and Irisin (LRT 0.62 ± 0.1 to 2.6 ± 0.4 ng/ml, P&lt;0.01; HRT 0.53 ± 0.1 to 2.8 ± 0.7 ng/ml, P&lt;0.01) while decreasing BDNF (LRT: 2747 ± 293 to 1081 ± 330 pg/ml, P&lt;0.01; HRT: 1976 ± 328 to 797 ± 160 pg/ml, P&lt;0.05). Acute exercise response of Musclin (AUC) was higher in LRT vs HRT (306 ± 74 vs. 88 ± 12 pg/ml×3h-1, P&lt;0.01) and elevated in HRT after training (221 ± 31 pg/ml×3h-1, P&lt;0.01). Training elevated SPARC (LRT: 2.4 ± 0.1 to 7.7 ± 1.3 ng/ml×3h-1, P&lt;0.05; HRT: 2.5 ± 0.13 to 11.2 ± 2.2 ng/ml×3h-1, P&lt;0.001) and Irisin (LRT: 1.34 ± 0.3 to 9.6 ± 1.7 ng/ml×3h-1, P&lt;0.001; HRT: 1.5 ± 0.5 to 12.1 ± 1.9 ng/ml×3h-1, P&lt;0.0001).ConclusionExercise training alters how myokines are secreted in response to acute exercise. Myokine responses were not robustly linked to adaptive potential in aerobic capacity, making them an unlikely regulator of adaptive traits.

172. Serum Igg Profiling Healthy 1- and 2- year Old Toddlers Reveals a Subgroup with Clinically Informative Reactivities to Pathogens and Autoantigens

Background The antibody repertoire in an infant/toddler develops in response to the microbiome, infections, environmental exposures, and vaccinations. Monitoring the specificity of these antibody responses in normal toddlers will provide indicators of disease susceptibility. Methods The serum Immunoglobulin (Ig)G and IgM antibody reactivity patterns in 1- and 2-year-old healthy toddlers was determined by examining the Ig specificity to diverse infectious agents, autoantigens and vaccine antigens with an antigen array. The toddlers were stratified based on their antibody reactivity to these diverse antigens with a normalized fluorescence intensity measure. Repeat profiling was performed at year 2 to reveal longitudinal changes in the IgG and IgM responses. Clinical information, along with DNA sequencing, and selected cytokine assays were used to establish an odds ratio for immune disease potential among the cohort. Results Healthy 1- and 2- year old IgG responses revealed cohorts of low, moderate, and high Ig responder groups that was unconnected with total serum IgG levels. The high responder group had elevated IgG reactions to selected pathogens, particularly viruses as well as to autoantigens. This high reactivity group, representing 17% of the cohort, had high odds ratios with maternal gestational diabetes, age, and a family history of asthma. While all toddlers developed strong antibody responses to Measles-Mumps-Rubella vaccines (MMR), more variation was noted towards other vaccines. In infections to Molluscum contagiosum, the IgG serum levels were transient regardless of the responder group. The high responder group had DNA polymorphisms linked to enhanced immune responses that correlated with elevated cytokine levels as well as eczema and asthma. A subset of toddlers has strong IgG responses to pathogens and vaccines Conclusion A subset of normal healthy toddlers has a high potential for immune system abnormalities and autoimmunity based on higher serum antibody responses to pathogens and autoantigens, genetic polymorphisms, and elevated cytokine responses. Disclosures All Authors: No reported disclosures