Fetal Origins: In the Womb, In the News

Fetal Origins focuses on how fetal development, in particular the interactions between mother and developing child, impact the rest of life.

David Barker, a physician and professor of epidemiology at the University of Southampton, initiated much of this line of research. The “Barker Hypothesis” posits that individuals born at low birth-weight will be at greater risk for health problems like coronary heart disease later in life.

More broadly, research has increasingly focused on how a range of factors during pregnancy and gestational development can impact adult health. This work often is placed under the rubric of “fetal origins,” where maternal stress, malnutrition, low birth weight, and other factors that impact development in the womb can create long-term changes in basic biological functioning.

Fetal Origins is now hitting the mainstream. Time has it on the cover this week, with a feature article by Annie Murphy Paul entitled How the First Nine Months Shape the Rest of Your Life.

The Time cover is of course meant only to sell magazines, so a naked, shapely but thin young white woman, vaguely curled in a fetal position, is plastered there in black-and-white. Unfortunately, this picture is basically the poster child for everything that Fetal Origins is not!

I am sure this young woman is as healthy as can be, and receives excellent nutrition and health care. Moreover, as young, white and surely wealthy, she represents the entirely wrong demographic for those women and children most likely to face problems due to fetal origins.

As the Time piece puts it:

The nutrition you received in the womb; the pollutants, drugs and infections you were exposed to during gestation; your mother’s health and state of mind while she was pregnant with you — all these factors shaped you as a baby and continue to affect you to this day.

The article doesn’t get much deeper than that, other than to note this is a new area of research, with plenty of controversy but also lots of research dollars behind it.

Research on fetal origins is prompting a revolutionary shift in thinking about where human qualities come from and when they begin to develop… And it makes the womb a promising target for prevention, raising hopes of conquering public-health scourges like obesity and heart disease through interventions before birth.

Over at Slate, Amanda Schaffer offers up a review as epistle of Annie Murphy Paul’s book, Origins: How the Nine Months Before Birth Shape the Rest of Our Lives.

Lessons from the Womb: Are Pregnant Women Really More Xenophobic? provides caution to temper Annie Murphy Paul’s fetal origins enthusiasm.

Your optimism is contagious. You write persuasively about the hope of reducing childhood obesity by helping women with gestational diabetes. The study you cite, which suggests the benefit of controlling blood sugar during pregnancy, is compelling to me, too. If I were to pick the area in which outreach to pregnant women might most improve children’s later health, I’d choose diabetes control (in addition, of course, to basics like prenatal vitamins and omega-3 fatty acids).

At the same time, I have not seen comparable evidence that reducing pregnant women’s stress can improve kids’ cognitive development to the extent that educational programs can. I’m also cautious about the promise that prenatal dietary supplements will turn out to forestall cancer later in life, another possibility you dangle in the book based mainly, it seems, on a small amount of early work in mice.

As an exploding area of research, it’s always good to consult the latest research. This 2009 review by Pathik Wadhwa et al., Developmental Origins of Health and Disease: Brief History of the Approach and Current Focus on Epigenetic Mechanisms, looks like a good place to start.

However, I want to highlight the work of the anthropologist Chris Kuzawa, associate professor at Northwestern, who has been the leader in developmental origins research within anthropology. His 2009 review article, written with Elizabeth Quinn, brings together evolutionary theory and developmental origins. (It looks like you can get the pdf here.)

Many biological systems have critical periods that overlap with the age of maternal provisioning via placenta or lactation. As such, they serve as conduits for phenotypic information transfer between generations and link maternal experience with offspring biology and disease outcomes. This review critically evaluates proposals for an adaptive function of these responses in humans.

Although most models assume an adult function for the metabolic responses to nutritional stress, these specific traits have more likely been tailored for effects during fetal life and infancy. Other biological functions are under stronger evolutionary selection later in life and thus are better candidates for predictive plasticity.

Given the long human life cycle and environmental changes that are unpredictable on decadal timescales, plastic responses that evolved to confer benefits in adolescence or adulthood likely rely on cues that integrate matrilineal experiences prior to gestation. We conclude with strategies for testing the timescale and adaptive significance of developmental responses to early environments.

Kuzawa, together with Elizabeth Sweet, then ties developmental research into social inequality, a much tighter coupling than a simple concept of “fetal origins of disease.” Their 2009 article addresses Epigenetics and the embodiment of race: Developmental origins of US racial disparities in cardiovascular health (pdf here).

There is extensive evidence for a social origin to prematurity and low birth weight in African Americans, reflecting pathways such as the effects of discrimination on maternal stress physiology. In light of the inverse relationship between birth weight and adult cardiovascular disease (CVD), there is now a strong rationale to consider developmental and epigenetic mechanisms as links between early life environmental factors like maternal stress during pregnancy and adult race-based health disparities in diseases like hypertension, diabetes, stroke, and coronary heart disease.

The model outlined here builds upon social constructivist perspectives to highlight an important set of mechanisms by which social influences can become embodied, having durable and even transgenerational influences on the most pressing US health disparities. We conclude that environmentally responsive phenotypic plasticity, in combination with the better-studied acute and chronic effects of social-environmental exposures, provides a more parsimonious explanation than genetics for the persistence of CVD disparities between members of socially imposed racial categories.

This research brings us full circle. It is not healthy, white women photographed on magazine covers who should be most concerned with the emerging research on fetal origins. Rather, people who care deeply about social inequality, and the intimate connection between mother and child in that context, are the ones who can look to fetal origins research with hope.

By linking social problems to biological outcomes through developmental origins, researchers, policy makers, community members and parents are in a stronger position to argue that quality of life matters, and that inequality is more than a social condition. The impact of environmental and maternal conditions on the biology of early development can have effects that last years longer than we imagined before. The body is a social slate.

Related Posts Plugin for WordPress, Blogger...
This entry was posted in Body, Development, Inequality, Plasticity, Variation. Bookmark the permalink.

Comments are closed.