Weighing the Future

Race, Science, and Pregnancy Trials in the Postgenomic Era

Natali Valdez

• Editorial: University of California Press
• Año: 2021
• ISBN:
  9780520380158
• Edición: 1
• Categoría: Sciences sociales
• Categoría: Anthropologie

Epigenetics, the study of heritable changes in gene expression, has been heralded as one of the most promising new fields of scientific inquiry. Current large-scale studies selectively draw on epigenetics to connect behavioral choices made by pregnant people, such as diet and exercise, to health risks for future generations. As the first ethnography of its kind, Weighing the Future examines the sociopolitical implications of ongoing pregnancy trials in the United States and the United Kingdom, illuminating how processes of scientific knowledge production are linked to capitalism, surveillance, and environmental reproduction. Natali Valdez argues that a focus on individual behavior rather than social environments ignores the vital impacts of systemic racism. The environments we imagine to shape our genes, bodies, and future health are intimately tied to race, gender, and structures of inequality. This groundbreaking book makes the case that science, and how we translate it, is a reproductive project that requires feminist vigilance. Instead of fixating on a future at risk, this book brings attention to the present at stake.

Part I

1 Epistemic Environments

REPRODUCING SOLUTIONS TO PAST, PRESENT, AND FUTURE MATERNAL HEALTH

The Motherwell study, named after the town it was located in, Motherwell, Scotland, was designed by Dr. Grieve, the local obstetrician. Between 1952 and 1976, Dr. Grieve implemented a unique nutritional intervention with thousands of women, from the main hospital of the town.¹ Dr. Grieve’s intervention included a calorie-controlled, low-carbohydrate, and high-protein diet (primarily red meat). The intervention prohibited women from eating bread, potatoes, prunes, plums, bananas, canned fruit, nuts, or dates, and they were not allowed to smoke, unlike other women at the time. Dr. Grieve also gave all the pregnant women strict weight gain limitations and warned that excessive weight gain would cause preeclampsia, which was consistent with the medical advice given at the time.²

More importantly, all the women in the study were required to eat one pound of red meat each day.³ Dr. Grieve designed this “Atkins-type” diet because he had an interest in body building and believed that this approach during pregnancy would promote fetal growth.⁴ In a booklet that provided instructions for the diet, Dr. Grieve wrote: “Quantity (of meat) is more important than quality. As it may be difficult to eat enough meat at meal times, the use of cooked meat, especially corned beef, rather than fruits or biscuits, is advised to assuage hunger between meals.”⁵

The Motherwell study was implemented for over twenty years, and it generated large amounts of data and helped recruit many women and their children into subsequent follow-up studies.⁶ The findings were also influential in the creation of global health policies related to maternal nutrition and weight. For instance, the study informed the maternal nutrition and weight guidelines in the United States and United Kingdom in the 1970s, and the follow-up studies were influential in shaping epigenetic and developmental origins of health and disease (DOHaD) claims about the impacts of maternal nutrition across the life course.

In the 1970s, the results of the Motherwell study found that women who received Dr. Grieve’s intervention had smaller babies than women in neighboring towns. Following these results, scientific consensus further developed around the idea that restricting maternal weight did not improve infant health. One other finding from the study that did not receive much attention was that infants born within the Motherwell study had low birth weights and lower rates of mortality compared to those born to women in other parts of Europe and Scandinavia who experienced restricted maternal weight gain due to war and famine. This finding was counter to the existing claims that causally connected low birth weight and infant mortality.

That is, despite the low birth weights among the infants in Dr. Grieve’s study, they still had a higher chance of living than infants born during famine and war who also had low birth weights. Might these contradictory differences in birthweight and mortality point to the role of the political and ecological environment that infants are born into, not only maternal weight and diet? Instead of examining how health risks linked to low birth weight and maternal weight are complexly related to environmental conditions during pregnancy, the interpretations of the Motherwell study focused entirely on creating health policies that strictly defined women’s weight during pregnancy.

The Motherwell study offers an entry point for assessing the social, political, and scientific landscapes of prenatal nutrition interventions across the past and present. It represents an older kind of prenatal nutrition experiment, prior to the standardization and ethical implementation of randomized clinical trials (RCTs) with pregnant women. Nevertheless, core aspects of the Motherwell intervention remain similar to current “cutting-edge” prenatal lifestyle interventions. Despite the significant technological and ethical changes in pregnancy studies since the 1950s and a paradigmatic shift in science that often characterizes the postgenomic era, the content of the nutritional intervention itself and the premise that maternal weight and diet should be intervened in prevails as the dominant approach to maternal health care.

Yet to date, the hundreds of completed pregnancy trials that have implemented lifestyle interventions in diet and exercise have not found any conclusive evidence that prenatal nutritional interventions reduce pregnancy complications or improve infant health outcomes related to diabetes or obesity.⁷ Based on the current results of prenatal nutrition trials, it is not possible to make causal, linear associations between maternal nutrition and weight only and metabolic syndromes in future generations. Focusing on maternal diet alone ignores the material and bodily effects of other intersecting aspects of the environment. Despite this poor record, the growth and investment in lifestyle interventions in diet and exercise during pregnancy remains impressively high.

How is it that current science cannot imagine other ways to interpret and evaluate existing data on maternal nutrition and health? The Motherwell findings pointed to existing environmental differences that distinguished health outcomes across infants born in different social and political milieus. These data existed in the late 1970s. More importantly, how is it that scientific communities centered in the Global North continued to design, fund, and implement nutritional interventions in 2015 that were similar to the dietary interventions of 1955? What enduring aspects from the mid-twentieth century continue to shape the current epistemic environments, such that imagined solutions to maternal and future health remain limited?

In what follows, I contextualize relevant scientific theories and methodologies such as postgenomics/epigenetics, DOHaD, and the RCT method, and how they intersect at the site of pregnancy trials.⁸ In so doing, I outline the scientific and technological shifts that have taken place since the Motherwell study. Then I analyze these scientific fields, theories, and methods from a feminist and critical race perspective. In doing so, I illuminate the contours of past and present epistemic environments by interweaving politics of race, gender, and power relations. Finally, I expand on my own approaches to ethnographically studying pregnancy trials. Overall, this and the next chapter reflect the durability of individualized lifestyle interventions during pregnancy.

SCIENTIFIC FIELDS, DEFINITIONS, AND METHODS

Postgenomics

The postgenomic era is often used as an umbrella term to characterize the period following the sequencing of the human genome, beginning around the early 2000s. Although there is no clear consensus on whether postgenomics is a new scientific paradigm, the “post” prefix indexes a shift in understanding the significance of genes and gene-environment interactions. Prior to postgenomics, the gene-centric approach to genetics and genomics dominated the scientific imaginary of the last half of the twentieth century. The gene was understood to carry all the necessary information for organisms to develop and function. At the peak of the genetic paradigm, the Human Genome Project (HGP) sequenced the entire human genome.⁹ The HGP was an endeavor full of promise and expectations, but once the project was completed in the late 1990s, scientists and the general public were surprised by the results. The HGP concluded that humans have far fewer genes than originally estimated, and only a fraction of the genome consists of genes that are used to make proteins.¹⁰ That is, genes alone could not explain human variability or biological development. Other materials and mechanisms were at play in shaping how parts of the genome are regulated and expressed. The disenchantment with genetics as the blueprint of life opened up a space for the development of postgenomics and a newly enlivened interest in epigenetics as a field that does not center genetic determinism.¹¹

Postgenomic science includes the methodological, conceptual, and technical innovations in sequencing genomes and the expansion of biomarker development and analysis.¹² The root term genomics is complicated to define because it is continuously unfolding and changing. A capacious understanding of genomics includes genomes (all the genes that provide instructions and information for protein synthesis) and the material in and around the genome. Biomarkers are biological signs or indicators connected to particular health outcomes and are analyzed in blood, urine, or tissue samples. They become important for tracing epigenetic modifications across maternal and infant environments, an aspect I return to in chapter 6. Importantly, the fields of epigenetics and DOHaD have significantly changed the postgenomic landscape, particularly in the realms of maternal health and reproductive sciences.

Epigenetics

Epigenetics is a key field within postgenomics. The Greek prefix “epi” literally means “on top” or “above”; broadly defined, epigenetics refers to the study of gene-environment interaction and genetic expression.¹³ In current understandings, epigenetics can include a variety of mechanisms involved in genetic programming, such as DNA methylation, histone modification, and noncoding RNAs, as well as the regulation of chromatin structure.¹⁴ For instance, the environment around the DNA can include methyl groups that attach to parts of the DNA; this process is called methylation, and it can impact the instructions for an organism’s development. Previously, scientists did not consider these processes to be important parts of genetic expression; however, epigenetic science spotlights these processes as important to the modification of genes and their expression.

The definition of epigenetics has changed over time. When Conrad Waddington, a British scientist, first coined the term epigenetics in the mid-twentieth century, it was derived from the term epigenesis, or the process of development through differentiation.¹⁵ Waddington drew from the notion of acquired characteristics, or genetic assimilation, to illuminate epigenetic processes.¹⁶ He explained that genetic assimilation occurs as a result of complex genetic interactions during development, and that these processes are flexible. For instance, Waddington claimed that an organism could assimilate or rather “remember” or embody environmental stress that occurred in past generations.¹⁷

The notion of genetic assimilation or acquired characteristics is similar to a much older concept of biological development credited to Jean-Baptiste Lamarck, a French naturalist (1744–1829). In the early nineteenth century Lamarck proposed a theory of inheritance through acquired characteristics (a giraffe acquires a long neck in response to surrounding tall trees, which were a main food source). By the late 1800s Lamarck’s work was overshadowed by the dominant theory of evolution developed by British collaborators Alfred Wallace and Charles Darwin.¹⁸ The notion of Darwinian evolution was supplemented by Gregor Mendel’s theory of genetic inheritance, published in the early 1900s. Mendel’s work explained that genes from “mother” and “father” are inherited by the offspring.¹⁹ Whereas Lamarck’s work is referenced as “soft inheritance” because it denotes flexibility and malleability of inheritance in relation to the environment, Mendel’s work became known as “hard inheritance,” characteristic of genetic determinism.²⁰

Epigenetics in humans fundamentally challenges traditional notions of inheritance. Whereas genetics is defined by Mendelian inheritance or the idea that discrete pairs of genes are passed from parent to child only, epigenetics is defined as non-Mendelian inheritance, with the potential of both transgenerational and intergenerational inheritance. In epigenetics, environmental factors can influence genetic expression and regulation, and epigenetic modifications from past generations can be carried on to shape development across generations. As Moshe Szyf explains, “it was generally believed that most of the epigenetic information is erased during early gestation, and if this erasure were complete then errors in the epigenetic markings would...