Decline of semen quality during IVF is not associated with subjective male stress

The aim of the present study was to assess if semen quality declines during in vitro fertilization （IVF） and whether or not this phenomenon is triggered by chronic male stress. In order to test this hypothesis, we first investigated a retrospective cohort of 155 male IVF patients （testing cohort）. Subsequently, we started a prospective cohort study in men undergoing their first IVF and assessed semen quality and subjective male chronic stress using a validated tool, i.e. the Fertility Problem Inventory （FPI） questionnaire. The association between stress and sperm quality decline measured 4-6weeks before the start of IVF （T1） and at the day of oocyte retrieval （T2） was the primary outcome. Live birth rate, first trimester abortion and rate of poor responders were secondary outcomes. In the testing cohort, mean progressive motility, but not mean sperm density significantly declined. There were 78/154 （51%） men who showed a decline in semen density and 50/154 （32%） men who showed a decline in progressive motility. In the validation cohort, progressive motility declined, whereas, sperm density increased from T1 to T2. Of 78 men, 27 men had increased stress （FPI-score 〉 146）. Sperm density and progressive motility were not significantly different in men with and without stress. However, in the presence of male stress, couples had a higher rate of poor responders, miscarriages and a lower rate of live births. Subjective stress is not associated with a decline in semen quality observed during IVF but may be associated with adverse ore^nancv outcome.

Stochastic Epidemic Model of Covid-19 via the Reservoir-People Transmission Network

The novel Coronavirus COVID-19 emerged in Wuhan,China in December 2019.COVID-19 has rapidly spread among human populations and other mammals.The outbreak of COVID-19 has become a global challenge.Mathematical models of epidemiological systems enable studying and predicting the potential spread of disease.Modeling and predicting the evolution of COVID-19 epidemics in near real-time is a scientific challenge,this requires a deep understanding of the dynamics of pandemics and the possibility that the diffusion process can be completely random.In this paper,we develop and analyze a model to simulate the Coronavirus transmission dynamics based on Reservoir-People transmission network.When faced with a potential outbreak,decision-makers need to be able to trust mathematical models for their decision-making processes.One of the most considerable characteristics of COVID-19 is its different behaviors in various countries and regions,or even in different individuals,which can be a sign of uncertain and accidental behavior in the disease outbreak.This trait reflects the existence of the capacity of transmitting perturbations across its domains.We construct a stochastic environment because of parameters random essence and introduce a stochastic version of theReservoir-Peoplemodel.Then we prove the uniqueness and existence of the solution on the stochastic model.Moreover,the equilibria of the system are considered.Also,we establish the extinction of the disease under some suitable conditions.Finally,some numerical simulation and comparison are carried out to validate the theoretical results and the possibility of comparability of the stochastic model with the deterministic model.

Re： Commentary on ＇Decline of semen quality during IVF is not associated with subjective male stress＇

We thank the commentator for his valuable insights as expressed in the above commentary. We fully agree that numerous lines of evidence support the assumption that male as well as female stress and the interaction of the stressed couple plays a role in the success of assisted reproduction. Furthermore, it is common ground that in vitro fertilization （IVF）/intracytoplasmic sperm injection （ICSI） couples are an especially vulnerable patient collective in this respect. We have, however, not yet identified the optimal means of measuring stress or the relevant aspects of it during the management of couples undergoing IVF/ICSI. This fact is also highlighted by our findings,t Further work is necessary to identify efficient and reliable tools to measure and treat stress in males and females undergoing IVF/ICSI with the goal of further improving reproductive outcomes.