A study conducted at Soroka Medical Center and led
by Dr. Eliahu Levitas, Senior physician in the
Fertility and In-Vitro Fertilization Unit examined
the impact of climate on the quality of sperm and
analyzed it in the different months of the year.
The study showed that sperm quality increased in the
winter and corresponded to the rise in the number of
births in the hospital nine months later.
The study, recently published in the American
Journal of Obstetrics & Gynecology, was based on
6,455 semen samples from 6,447 men at Soroka Medical
Center. The statistical analysis that sorted the
samples according to the season they were taken
indicated an increase in the concentration and
quality of the sperm in the winter. Motility
differences were also found that could influence the
chances for pregnancy.
Even though sperm speed was greater in summer than
in winter, fewer of these sperm exhibited
progressive motility, that is, straight line
movement essential for fertility.
Also, in comparing the summer samples with those
taken in winter, the winter sperm showed fewer
abnormalities.
A comparison of the number of births at Soroka’s
Saban Maternity Center, the busiest delivery room in
the country, shows seasonal variations that are
consistent with the seasonal variations of the sperm
samples.
The study presented data on the number of births at
Soroka Medical Center from 2005 to 2010, totaling
79,038. The distribution by season showed the
highest number of births in the fall (September,
October, November), 22,732 in the five years.
Whereas in the spring (March, April, May),
corresponding to conception the previous summer, the
lowest number of births was recorded, 17,753 in the
five years.
Dr. Eliahu Levitas, Senior physician in the
Fertility and IVF Unit at Soroka Medical Center:
“The findings attest to a general increase in the
quality of sperm in the winter and a decline in
summer. This may be explained by the negative effect
of heat on the testicles. The testicles are external
to the body, maintaining a temperature 1.5 to 2
degrees Centigrade lower than the body. Couples
struggling to conceive should perhaps be more alert
to the seasons of the year and increase their
efforts particularly in the colder months”.
For more information
American Journal of Obstetrics & Gynecology
Seasonal variations of human sperm cells among 6455
semen samples: a plausible explanation of a seasonal
birth pattern
http://www.ajog.org/article/S0002-9378%2813%2900146-4/abstract
(MDN)
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