Can the right foods really improve your chances of having a baby? Here are the facts.
Visit any online fertility chat room, and one of the main topics of debate will probably be what to eat to maximise your chances of conceiving. In addition to the wealth of supplements promoted as being fertility-boosting, there is also an array of foods that are supposed to help achieve a healthy pregnancy.
Amid all the myths and marketing, what is the actual evidence for using certain foods to enhance male and female fertility, and support the developing fetus?
For a start, when it comes to supporting a healthy pregnancy and fetus, certain nutrients really can make a difference – such as folic acid. When taken before and during pregnancy, it has been shown to help prevent both anencephaly, a birth defect of the baby’s brain, and spina bifida, which affects the baby’s spine.
Because these defects develop very early in the pregnancy, often before a woman knows she is pregnant, the US Centers for Disease Control and Prevention recommend that all women of reproductive age take 400 micrograms (mcg) of folic acid each day. Fortifying staple foods such as cereals with folic acid may offer even more powerful protection, because many pregnancies are unplanned. It is estimated that, in 2019, effective fortification programmes prevented 22% of potential cases of folic-acid-preventable spina bifida and anencephaly, worldwide.
Folic acid may have an additional benefit: when taken as a supplement by women trying to conceive, it may increase the chance of getting pregnant, though there is a need for further trials to confirm this.
What about other foods and supplements? Is there such a thing as a “fertility diet” that will maximise your chances of conceiving?
A study of couples undergoing IVF found that men’s meat consumption, and especially the type of meat they ate, affected the outcome
To answer that question, it helps to break down the main reasons for infertility. In the United States, after one year of having unprotected sex, 15% of couples are unable to conceive. There are many potential causes. On the female side, the ovaries may be unable to produce healthy eggs, or the egg may not be able to move from the ovaries to the womb – for example, due to blocked fallopian tubes. Even if the egg makes that journey successfully, it may then not attach to the lining of the womb, or not survive once it has attached.
On the male side, the quality of sperm cells is crucial for fertility. This includes their ability to move efficiently (motility), their shape and size (morphology), and how many there are in a given quantity of semen (sperm count). A range of factors can threaten sperm quality, including environmental problems such as pollution (read BBC Future’s report on the global decline in sperm quality). Even after tests, the cause of infertility may not always be clear: about 15% of infertility cases remain unexplained.
While no individual food or supplement will be a quick fix for any of these potential issues, experts say diet can play a beneficial role throughout the process of trying to conceive and beyond.
Most obviously, being well-nourished is crucial. The consequences of malnutrition can be devastating for prenatal health.
Arguably the best-known findings in this area come from a study of babies conceived during the so-called “Dutch Hunger Winter” of 1944; an eight-month famine that occurred when the Nazis cut off food supplies into the Netherlands at the end of World War II. The mothers-to-be were surviving on only 400 calories a day, a fraction of the intake necessary for a healthy pregnancy. The babies conceived during that time faced a range of adverse health consequences, including being shorter and thinner than those born before or after them, and having smaller heads. As adults, they had higher rates of obesity, diabetes and schizophrenia, and tended to die younger.
For those who do have access to sufficient food, it is still important to obtain the right mix of nutrients. While discussions around beneficial foods often focus on female fertility, there has been a growing awareness of how diet can also affect male fertility.
A 2015 study of couples undergoing IVF found that men’s meat consumption, and especially the type of meat they ate, affected the outcome, as measured by fertilization rates. Eating more poultry had a positive impact on fertilisation rates, whereas eating processed meat (such as bacon and sausages) had a negative impact. Men who ate the least processed meats, averaging fewer than 1.5 servings a week, had an 82% chance of achieving pregnancy with their partner – while men who ate the most processed meats, with an average of 4.3 servings a week, had just a 54% chance.