There have been conflicting results from studies on the relationship between caffeine and infertility; some studies show that up to four cups per day are permissible while others show fertility is harmed from just one cup of Joe a day.
In 2011 a study by researchers at the University of Nevada sought to establish exactly how caffeine interferes with fertility and discovered that caffeine has an adverse effect on the fallopian tubes of mice and probably women too.
The study showed that caffeine paralyzes the special 'pacemaker' cells in the walls of the fallopian tubes which control the rhythmic contractions of the tube walls. It was previously though that the cilia - which are tiny hair-like projections that line to interior of the tubes - were primarily responsible for moving the egg/embryo along but it seems the tube walls are equally if not more important.
The egg/embryo must be transported through the tube within a very specific time window for it to arrive at the uterus when the lining is most receptive to implantation. If the fallopian tubes do not rhythmically move the egg and/or embryo along in perfect time conception may be stymied.
The fallopian tubes perform very finely tuned functions: they waft the egg - and then the embryo - along and 'hold' the embryo at specific points while secreting nutrients to enable the embryo to reach the uterus at just the right time for implantation to occur. A HSC test which is commonly used to establish whether fallopian tubes are open does simply that, it checks if fluid can pass through the tube. The test cannot establish how ‘functional’ the tubes are or how well they move the egg along.
If you want to achieve peak fertility you would be well advised to avoid caffeine containing beverages. Caffeine consumption is associated with miscarriage too so it is a good idea to avoid caffeine in pregnancy also. The lead researcher - Sean Ward - a professor of medicine at the University of Nevada commented that:
"This provides an intriguing explanation as to why women with high caffeine consumption often take longer to conceive than women who do not consume caffeine..."
There are other ways in which caffeine interferes with fertility too; caffeine compromises the blood flow within the arteries which supply blood to the ovaries and uterus, thus raising the pulsatility index. Some fertility clinics routinely measure the blood flow of these arteries before IVF knowing that if the flow is compromised implantation is unlikely and the ovaries will not perform as well. These clinics warn their patients to avoid all caffeine in the 24 hrs prior to the test as it will likely skew the reading. If the flow is poor the cure is a one month course of a specific acupuncture treatment proven restore good blood flow.
If you are choosing a decaffeinated coffee or tea, check that it has been water processed to remove the caffeine to reduce the likelihood of chemical contaminants from the decaffeinating process.
This article is purely for educational and informational purposes and is not intended to substitute for medical diagnosis or treatment for which you should consult a physician.
British Journal of Pharmacology press release May 26 2011 ‘Why Caffeine Can Reduce Fertility In Women’