Parental subfecundity or use of MAR doesn't negatively impact reproductive health of sons
Infertility is an increasing global health problem,affecting approximately 15% of couples worldwide and male factor infertility isa major contributing factor. The decline in couple fecundity presumably iscaused by biological, social, and behavioral aspects. It has been suggestedthat family planning and use of contraception during the past century haveincreased subfecundity. The most fecund couples have fewer children, whereascouples with low fecundity produce more children than before due to fertilitytreatment. This hypothesis assumes that intergenerational transmission ofsubfecundity is substantial, which is poorly documented.
During the last decades, an increasing number of childrenhave been conceived by use of medically-assisted reproduction (MAR).Medically-assisted reproduction consists of a wide range of treatment optionsdepending on the underlying cause of infertility; from ovulation induction andintrauterine insemination (IUI) used in couples without male factorinfertility, to the more invasive and advanced techniques, such as in vitrofertilization (IVF) or intracytoplasmic sperm injection (ICSI). It is wellknown that poor semen quality is a major contributing cause of coupleinfertility, and for years, couples where the male has severely poor semenquality needed donor sperm to achieve a pregnancy by IVF.
Male factor infertility remains a major global healthproblem and natural concerns have been raised on whether poor semen quality isthe result of intergenerational transmission to the next male generations.Further, with the increasing use of MAR, in particular IVF and ICSI, there is aneed to investigate if any paternally inherited or technically associatedadverse effects may exist on reproductive health.
A cohort study carried out by Linn H. Arendt and team wasbased on total of 1,058 men in the Fetal Programming of Semen quality cohortfrom the Fetal Programming of Semen quality (FEPOS) cohort, a subcohort nestedwithin the Danish National Birth Cohort (DNBC).
From 2017–2019, men were recruited and provided semen andblood samples. Information on parental time to pregnancy and use ofmedically-assisted reproduction (including type of treatment) as well asdemographic, health, and lifestyle factors were available. Semencharacteristics (semen volume, sperm concentration, total sperm count, spermmotility, and morphology), testicular volume, and reproductive hormone levels(follicle stimulating hormone, luteinizing hormone, testosterone, estradiol,sex hormone-binding globulin, and free androgen index) were noted.
Overall, semen quality and levels of reproductive hormoneswere not lower among sons of subfecund parents reporting a time to pregnancy>6 months or use of intrauterine insemination. Sons conceived after in vitrofertilization or intracytoplasmic sperm injection, had a higher semen concentration(29%) and a higher percentage of sperm with normal morphology (20%), but with95% CI overlapping the null. Moreover, these sons had slightly higher estradiollevels (30%). The absolute differences seen were small, and the clinicalsignificance of these differences are unknown.
In this nationwide population-based cohort study, authorsfound no major difference in semen quality or reproductive hormones in sonsconceived by subfertile couples or with the use of MAR. Thus, these data do notsupport the hypothesis that parental subfecundity was inherited, thus,affecting the semen quality of male offspring or that reproductive health insons was affected by parental MAR treatment.
In conclusion, authors found no evidence to support thehypothesis that parental subfecundity or use of MAR negatively affectsreproductive health in male offspring measured by semen quality or testicularvolume. However, they found a slightly altered hormonal profile of menconceived following IVF or ICSI. These results are reassuring for the manycouples worldwide struggling with subfecundity, but contradict previousfindings. The findings of this study thus need replication in futureindependent studies.
Source: Linn H.Arendt, Anne Gaml-Sorensen, Andreas Ernst; Fertilityand Sterility
