Effect of advanced paternal age on reproductive outcomes in IVF cycles of non-male-factor infertility: a retrospective cohort study

Advanced paternal age has been overlooked,and its effect on fertility remains controversial.Previous studies have focused mainly on intracytoplasmic sperm injection(ICSI)cycles in men with oligozoospermia.However,few studies have reported on men with semen parameters within reference ranges.Therefore,we conducted a retrospective cohort study analyzing the reproductive outcomes of couples with non-male-factor infertility undergoing in vitro fertilization(IVF)cycles.In total,381 cycles included were subgrouped according to paternal age(<35-year-old,35–39-year-old,or≥40-year-old),and maternal age was limited to under 35 years.Data on embryo quality and clinical outcomes were analyzed.The results showed that fertilization and high-quality embryo rates were not significantly different(all P>0.05).The pregnancy rate was not significantly different in the 35–39-year-old group(42.0%;P>0.05),but was significantly lower in the≥40-year-old group(26.1%;P<0.05)than that in the<35-year-old group(40.3%).Similarly,the implantation rate significantly decreased in the≥40-year-old group(18.8%)compared with that in the<35-year-old group(31.1%)and 35–39-year-old group(30.0%)(both P<0.05).The live birth rate(30.6%,21.7%,and 19.6%)was not significantly different across the paternal age subgroups(<35-year-old,35–39-year-old,and≥40-year-old,respectively;all P>0.05),but showed a declining trend.The miscarriage rate significantly increased in the 35–39-year-old group(44.8%)compared with that in the<35-year-old group(21.0%;P<0.05).No abnormality in newborn birth weight was found.The results indicated that paternal age over 40 years is a key risk factor that influences the assisted reproductive technology success rate even with good semen parameters,although it has no impact on embryo development.

The interaction effect between advanced paternal age and paternal obesity is associated with the low implantation rate in couples with unexplained recurrent pregnancy loss

Objective:To explore the roles of advanced paternal age(APA)and abnormal paternal weight on embryo quality and pregnancy outcomes for unexplained recurrent pregnancy loss(uRPL)couples who underwent preimplantation genetic testing for aneuploidies(PGT-A).Methods:This study included 779 uRPL couples who underwent their first PGT-A cycles between 2014 and 2018.Male patients’aging and nutritional status were quantified by paternal age and body mass index(BMI).Routine semen parameters and sperm DNA fragmentation index(DFI)were used to reflect the seminal quality.Blastocyst formation rate and aneuploidy rate were used to reflect the embryo quality.Cycle cancellation rate,implantation rate,pregnancy loss rate,and live birth rate were measured to evaluate the treatment efficiency from IVF.To remove the interference of maternal age,only the women younger than 38 years old were included.After univariate screening,interaction tests were performed in a generalized linear model(GLM)to further examine the effects of paternal age and BMI on each outcome indicator.Results:In the total population(779 cycles),there were no statistical differences in aneuploidy rate,cycle cancellation rate,implantation rate,pregnancy loss rate,and live birth rate,whether stratified by paternal age or paternal BMI.Similar results occurred in the younger men(<40 y.o.,633 cycles).Conversely,among the men with advanced age(≥40 y.o.,146 cycles),there were statistical differences between the three BMI groups in four semen parameters(total sperm number,total motility,progressive motility,and total motile sperm count),implantation rate,and live birth rate.After interaction testing,the results of GLM suggested that the interaction effect between APA and paternal obesity was associated with the low implantation rate of uRPL couples.Conclusions:For the uRPL couples seeking for PGT-A treatment,if the male patients have both advanced age and obesity,their spouses are at higher risks for embryo implantation failure.

Influence of age at mating on the reproductive performance of Parthenium beetle, Zygogramma bicolorata （Coleoptera： Chrysomelidae）

Age-specific mating incidence, sexual maturation and effect of age at mating on reproductive performance of the Parthenium beetle, Zygogramma bicolorata Pallister, was studied. Based on 50% mating incidence the calculated age of sexual maturation of males and females was 10.5 and 11.1 days, respectively, which was not statistically signifi- cant. However, on the basis of age at first mating, that is, sexual maturity, females matured 2 days earlier than males. Fecundity, pre-oviposition, oviposition and post-oviposition period and female longevity appear to be influenced by female age at mating with repro- ductive performance peaking at 30 days. On the other hand, egg viability was influenced by male age and was highest when males mated at the age of 40 days. To summarise, egg production and timing of egg deposition was female age-dependent, whereas egg fertility was male age-dependent. It was also observed that females mated at a later age and laid a higher number of eggs immediately after mating than did earlier mated females. This was ostensibly in a bid to increase fitness by maximizing reproductive output in the reduced life span available. This is the first investigation on the effect of age of females at mating on reproduction in this beetle.