Whenever someone asks me “what else can we do to boost our chances?” it represents one of the most exciting and challenging moments of our interaction. It’s exciting because it shows a willingness to make changes in their current diet and/or lifestyle. It’s challenging because there are no simple answers and most of the data is rather loosely supportive of the recommendations. Fortunately better studies are coming out all the time.
The January 2015 Issue of the journal Fertility & Sterility put this topic front and center. The journal opened with a commentary that pointed out the fact that each egg–even those from fertile egg donors–has no more than a 40% chance of becoming a successful pregnancy. Therefore, we need to look beyond what we do with the sperm and eggs and also direct our attention toward what else can impact their quality. A “global medicine approach” proposes that we look at the nutritional status, environment and lifestyle for additional answers and better outcomes. The journal went on to present three papers to bring us closer to that goal.
The first study looked at infant birthweight and the risk–several decades later–of male factor infertility. Specifically, they were looking at the theory that some male infertility begins in the womb prior to birth. Other studies have found results suggesting this happens for women; that low birthweight may increase the risk of longer time to conception and a higher risk of diminished ovarian reserve. That prompted this research to determine if the same might be true in men. It was. They found that men that were born with a birthweight less than 2,500 gm (normal is 2,500 to 3,500 gm at term) were at a higher risk of having a low sperm count and their sperm was more likely to have damaged DNA. They also tended to be overweight or obese which is also associated with male factor infertility. So nutrition during pregnancy can have lasting implications for the children that are born.
A second article summarized the concept of “ecofertlility;” environmental toxins that may alter fertility. The examples that they focused on were those that were most common and most easily controlled, tobacco and marijuana since there is typically a choice to use or not use these substances. The authors reviewed a variety of studies that consistently demonstrate that women that are cigarette smokers tend to take about a year longer to conceive, have a higher rate of infertility and are more likely to have a diminished ovarian reserve than nonsmokers. Men were impacted similarly. Male smokers had a higher risk of abnormal semen analysis as well as a higher rate of erectile dysfunction. The authors also presented evidence that various substances produced by tobacco smoke appear in the fluid that surrounds the eggs and then have a very toxic impact. These substances may actually result in a higher rate of failed fertilization. This may explain why smokers have about a 40% lower pregnancy rate when undergoing IVF than nonsmokers. Even with sperm injection (ICSI) directly into the egg; the rate of “fertilization failure” is about three times higher in smokers. The impact of marijuana was more difficult to quantify. In men it has been linked to a higher risk of sperm abnormalities, as well as various hormonal dysfunctions including gynecomastia (increase in breast size), low libido and problems with erectile dysfunction. There is less data on women as exposure is difficult to accurately assess and monitor and correlate with egg function since exposure now may impact an egg many months (or even years) later.
Finally, in a third paper they reviewed the potential impact of one of the most widely studied chemicals that we’re all exposed to called bisphenol-A (BPA). This chemical was first produced in 1891. It was identified to have estrogen-like activity as far back as 1936. Unfortunately, that did not stop its production and distribution. Today it is recognized as one of the most ubiquitous hormone disrupting chemicals. About 20% of the BPA produced—nearly 3.4 million tons per year—is used to line various food containers. From there, it has clearly been shown to leech into the food that we eat and then contribute to various health problems like diabetes, obesity, heart disease, lung problems, kidney disorders as well as various reproductive problems. The data on its toxicity has been alarming enough to prompt Canada from banning its use in baby bottles (2008). More recently the European Union went a step further and banned its use entirely in 2011. Here in the US, there is just now legislation proposed to require clear labeling on food containers that contain BPA. The study authors went on to provide a further note of caution by providing evidence that two chemicals that have been proposed to replace it—BPS and BPF—may have similar negative effects based upon animal data. Human studies are pending. The bottom line is that we need to pay more attention to the chemicals that we use to package our food in as they may actually taint our food supply as well as reduce our health and fertility.
As a reproductive health specialist, I don’t want to alarm my patients but I also don’t want to marginalize the potential impact of our choices upon our ability to initiate a healthy pregnancy. Although walking the line between concern and unnecessarily upsetting people may be a delicate one; I do feel compelled to empower those that are willing to listen. Success is not just about what happens in the clinic—it begins at home.
[r1]Link to http://www.fertstert.org/article/S0015-0282(14)02274-2/abstract
[r2]Link to http://www.fertstert.org/article/S0015-0282(14)02383-8/abstract
[r3]Link to http://www.fertstert.org/article/S0015-0282(14)02354-1/abstract
[r5]Link to http://www.endocrine.org/membership/email-newsletters/endocrine-insider/2015/march-19-2015/endocrine-society-endorses-bpa-in-food-packaging-right-to-know-act