Circannual rhythm in human sperm count revealed by serially independent sampling

Tjoa, Wilie S.; Smolensky, Michael H.; Hsi, Bartholomew P.; Steinberger, Emil; Smith, Keith D.

doi:10.1016/s0015-0282(16)46580-5

Cited by 93 publications

(41 citation statements)

References 4 publications

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“…A major factor that has an immense impact on sperm count is seasonal changes, which is evident from the fact that sperm count differed by about 30% in summer from that in winter in all the four countries. This fact is also supported by all other previous studies, some including men of known fertility and some of known subfertility, which observed seasonal variations in sperm count being lowest during the summer and highest during autumn or winter (Gyllenborg et al, 1999;Maier, Newbold, & McLachlan, 1985;Spira, 1984;Tjoa et al, 1982). There are a few studies that could not detect any seasonal variations (e.g., Mallidis, Howard, & Baker, 1991).…”

Section: North America Numerous Studies Conducted In the Unitedsupporting

confidence: 81%

The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015

2016

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Reports regarding the changes in sperm concentration in different counties of the world are inconsistent. Furthermore, the reports that sprung up from specific epidemiological and experimental examinations did not include data of prior studies or geographical variations. The current study, following a previous report of massive fall in semen volume over the past 33 years, attempts to delineate the trend of altering sperm concentrations and factors responsible for this by reviewing article published from 1980 to July 2015 with geographic differences. The current study identified an overall 57% diminution in mean sperm concentration over the past 35 years (r = −.313, p = .0002), which, when analyzed for each geographical region, identified a significant decline in North America, Europe, Asia, and Africa. An increasing trend of sperm concentration was identified only in Australia. The association of male age with such a trend (R 2 = .979) is reported. The authors also correlated male fertility with sperm concentration. Thus, this comprehensive, evidencebased literature review aims to concisely and systematically present the available data on sperm concentration from 1980 to 2015, as well as to statistically analyze the same and correlate male health with the declining pattern of sperm count in a single scientific review to serve the scientific research zone related to reproductive health. It points to the threat of male infertility in times ahead.

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Section: North America Numerous Studies Conducted In the Unitedsupporting

confidence: 81%

The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015

2016

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“…Similarly the rate of ovulation was unimportant as only the cycles of treatment in which ovulation was confirmed endocrinologically were included. Seasonal variation in the quality of semen is well documented, with maximum sperm counts and density and semen volume at the end of winter and beginning of spring (February to March).2 3 Our results showed a distinct increase in rates of conception in early winter-that is, before the improvement in the quality of semen. By exclusion, therefore, we suggest that there is seasonal variation in the quality of the ovulated egg or endometrial receptivity, or both, and that the time of highest quality is early winter.…”

Section: Discussionsupporting

confidence: 52%

Seasonal distribution in conceptions achieved by artificial insemination by donor

Paraskevaides¹,

Gw²,

Naik³

1989

Intl J Gynecology & Obste

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The distribution of conceptions after artificial insemination from a donor was studied in 259 conceptions at an artificial insemination clinic and found to be seasonal. Conception was not influenced by the number of donors or patients attending the clinic, the frequency of inseminations, or medical skill. Conception was more common from early winter until early spring (October to March) with a peak in November. As variables such as frequency of intercourse and ovulation were irrelevant in these women and highest sperm counts occur from February to March these results suggested a seasonal variation in the quality of the ovulated egg or endometrial receptivity.The waste of eggs after ovulation (or preimplantation conceptuses) at specific times of the year has implications in the treatment of infertility, particularly for in vitro fertilisation and gamete intrafaliopian transfer.

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“…Sperm concentration, total sperm count per ejaculate and motile sperm concentration have been reported to be lower in the summer than in the winter [19][20][21][22] and even mild heat can temporarily reduce the number of sperm ejaculated after two to three weeks [23]. The effect of heat stress on spermatogenesis may further extend time to pregnancy and decrease birth rate in women [24].…”

Section: Introductionmentioning

confidence: 99%

Effects of paternal heat stress on the in vivo development of preimplantation embryos in the mouse

Zhu

Setchell

2004

Reprod. Nutr. Dev.

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-The objective of this study was to examine the effect of paternal heat stress on the in vivo development of preimplantation embryos in the mouse. Synchronised B6CBF1 female mice were mated either to a control male mouse or to one that had been exposed at 7, 21 or 35 days previously, for 24 h to an ambient temperature of 36 ± 0.3 °C and 66 ± 5.6% relative humidity. Embryos were collected from the oviducts of mice at 14-16 h, 34-39 h or 61-65 h after mating or from the uterus at 85-90 h after mating and their developmental status was evaluated morphologically. The number of cells within blastocysts was also determined using bisbenzimide-propidium iodide staining. Paternal heat stress 7 days before mating reduced the proportion of embryos developing from 4-cell (4-C) to morulae (M), hatched blastocysts, total blastocysts and the number of inner cell mass (ICM) and trophectoderm (TE) cells in the blastocyst. Paternal heat stress 21 days prior to mating reduced the proportion of 2-C and 4-C to M embryos with no embryos developing to blastocysts. There were also increases in the number of 1-C and abnormal embryos recorded at this time. Paternal heat stress 35 days before mating decreased the proportion of 2-C embryos, expanded blastocysts and ICM and TE cells in the blastocyst. These results support previous work demonstrating that both the sperm in the epididymis and germ cells in the testis are susceptible to damage by environmental heat stress, with spermatocytes being the most vulnerable. This study also demonstrates that subtle effects on the male such as a short exposure to elevated environmental temperatures can translate to quite profound paternal impacts on early embryo development.paternal heat stress / in vivo development / mouse preimplantation embryos

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Circannual rhythm in human sperm count revealed by serially independent sampling

Cited by 93 publications

References 4 publications

The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015

The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015

Seasonal distribution in conceptions achieved by artificial insemination by donor

Effects of paternal heat stress on the in vivo development of preimplantation embryos in the mouse

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