Emerging evidence shows that preconception health of the mother- and father-to-be — especially their diet and weight — affects fertilization, embryo development, and even their child’s risk of future cardiometabolic disease.
A series of three articles, published online April 16 in the Lancet, shine a light on this critical period.
“Most people are aware of prenatal and antenatal care, and their importance,” lead author of one of the articles, Judith Stephenson, MBBS, from University College London, UK, told Medscape Medical News, “but we’re saying you need to shift the focus further back in time.”
“There’s now a lot of compelling evidence, both from animal and human studies, that the nutritional status and health of the mother and father before conception has an important influence on the way the embryo develops, and that will then affect the infant and child health,” she noted.
Changes in embryo development can affect the child’s lifetime risk of cardiometabolic disease (hypertension, obesity, and type 2 diabetes), allergies, cancer, and neurologic impairment.
“Alongside continued efforts to reduce smoking, alcohol consumption, and obesity in the population, we call for heightened awareness of preconception health, particularly regarding diet and nutrition,” Stephenson and her fellow researchers urge.
Health care practitioners may see women of childbearing age when they are “getting a pregnancy test or fertility test kit, if they’ve had a miscarriage (and are maybe thinking about trying to conceive again), or [they are] going to a family planning clinic and wanting their contraceptive device taken out because they want to conceive,” Stephenson explained.
This is an ideal opportunity for physicians to provide advice about preparing for a healthy pregnancy.
“If you take a general health history and say, ‘Do you smoke? Do you drink alcohol?’ you could also say, ‘Are you contemplating having a baby in the next year or so?’ “
Physicians need to “be aware, raise the conversation, and support women and couples to make the health changes they need to make,” without being judgmental, she stressed.
Obesity, Poor Nutrition Are “Rife” in Women of Reproductive Age
In the first article, Stephenson and colleagues report that poor nutrition and obesity “are rife” among women of reproductive age, “and differences between high-income and low-income countries have become less distinct, with typical diets falling far short of nutritional recommendations in both settings and especially among adolescents,” they note.
For example, their analysis of 509 nonpregnant women of reproductive age who took part in the UK National Diet and Nutrition Survey showed that 77% of women aged 18 to 25 had a dietary intake of iodine below the recommended level. And 96% of woman aged 18 to 42 had iron and folate levels below recommended levels for pregnancy.
Moreover, 49% of the women were overweight or obese.
Preconception is typically defined as 3 months before conception, because fertile couples who plan to have a child will generally conceive within that time.
However, the researchers suggest that the preconception period should be extended. Although “optimizing nutrition, including folic acid supplementation, should coincide with the decision to become pregnant,” which can be within 3 months of a pregnancy, other changes can take much longer to accomplish.
For example, reaching a healthy weight should ideally be achieved “during the sensitive period of adolescence when most women will not be planning a pregnancy,” they advise.
This is especially important because 40% of pregnancies globally are unplanned, so efforts to improve nutrition and health behavior as a whole at a population level are needed.
Embryonic Development a Critical Time
In the second article, Tom P Fleming, PhD, Emeritus Professor of Developmental Biology at the University of Southampton, UK, and colleagues propose that “there is sufficient evidence from human and animal research showing that the periconceptional period is a key window during which poor maternal and paternal physiology, body composition, metabolism, and diet can induce increased risk of chronic disease in offspring.”
“We propose that the evidence for periconceptional effects on lifetime health is now so compelling that it calls for new guidance on parental preparation for pregnancy, beginning before conception, to protect the health of offspring,” they stress.
Stephenson explained: “Maternal obesity can cause lipids to accumulate in the developing egg and within the early embryo causing stress and damage to their metabolism, altering growth rates, and changing the pattern of gene expression.”
And “there’s good evidence…for example, [that] male obesity can reduce sperm fertility and motility and increase sperm abnormalities leading to poor quality embryos,” she added.
Strategies to Improve Preconception Health
In the third article, Mary Barker, PhD, Associate Professor in Psychology, also at the University of Southampton, and colleagues stress that new individual and population-level strategies are required to improve preconception health.
On an individual level, increased awareness about preconception health is needed among women and couples planning to become pregnant.
“Trying for a baby is often quite a private matter,” Stephenson noted, “and you don’t necessarily go around telling families, friends, or doctors that this is what you’re doing.” Couples may prefer to wait until 12 weeks of pregnancy to tell others, when miscarriage is less likely.
However, “during that time it would really help your baby and the pregnancy to take folic acid, eat a healthy diet (more fruits and vegetables, and less junk food), quit or reduce smoking (if you can’t quit altogether), and the same for alcohol and recreational drugs; all these things are important to do before conception.”
If you don’t know that, then for some issues, “you’ve missed the boat; [because] when you’re 12 weeks pregnant, you’re not going to get the [full] benefit of folic acid supplementation,” for example.
“Probably only a third of women [in the UK] who are actually planning to get pregnant will take folic acid before they become pregnant, because they don’t really know about it,” she continued.
The message to women is that “even if you’re young, fit, and healthy, not overweight, have a good diet, and exercise, you still should take folic acid tablets before [becoming pregnant].”
On a population level, some countries require fortification of foods.
In the United States, Canada, Chile, Costa Rica, and South Africa, after folic acid fortification of certain foods became mandatory, there was a reduction in the prevalence of neural tube defects.
However, folic acid fortification of certain foods is not mandatory in Europe or the UK.
And the World Health Organization recommends fortifying salt with iodine.
Barker and colleagues observer that trials of interventions to improve nutritional status before conception and birth outcomes are scarce, “but new trials are underway,” they conclude.
The series of articles was developed at a symposium funded by the Rank Prize Funds. The authors have reported no relevant financial relationships.
Lancet. Published online April 16, 2018. Article 1, Article 2, Article 3
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