Scientists Discover Hormones in Ancient Skeletons, Paving Path for Pregnancy Research

Researchers have developed a method to test ancient human remains for hormones associated with pregnancy, significantly advancing the field of archaeology. This breakthrough enables scientists to ascertain whether a woman was pregnant or had recently given birth at the time of her death. The study, published on October 2, 2023, in the Journal of Archaeological Science, reveals that key reproductive hormones—estrogen, progesterone, and testosterone—were detected in the hard tissues of skeletons dating back as far as 1,000 years.

Lead author Aimée Barlow, an archaeologist at the University of Sheffield in northern England, described the findings as a significant milestone. “We found a ‘hormone archive’ in skeletons and teeth,” Barlow stated in an interview. “This is a first. Nobody has ever detected these specific hormones in teeth or dental calculus before.” Notably, this marks the first successful measurement of progesterone in human bone tissue.

Detecting pregnancy in ancient remains has historically posed challenges. Scientists previously believed that the inorganic nature of hard tissues would prevent the preservation of such proteins. Barlow and her team, however, applied the enzyme-linked immunosorbent assay (ELISA) technique to samples from seven female and three male skeletons, which spanned from the first to the 19th centuries. ELISA is a well-established method for detecting and quantifying protein molecules, including progesterone, a critical biomarker for pregnancy.

The results indicated measurable levels of estrogen, progesterone, and testosterone in various skeletal and dental structures. The study concluded that high levels of progesterone in dental structures and calculus, along with the presence of estrogen in bone and a lack of testosterone in hard tissues, were consistent with pregnancy at the time of death.

Barlow emphasized that confirming the preservation of hormones in skeletal remains could eventually allow researchers to glean insights into reproductive histories. “This will be especially useful for historical periods where no written records exist,” she said. With further study, researchers may determine the age at which a woman first became pregnant, whether she experienced pregnancy loss, and the intervals between births if she had multiple children.

Future Research Directions

Despite the promising results, Barlow acknowledged the need for further development of the technique. Establishing baseline hormone levels in skeletal tissues requires more extensive studies, including samples from living individuals with detailed medical histories. “We need to understand the fundamental science,” she noted, advocating for research on how these hormones are incorporated into and stored within different tissues. Additionally, exploring the preservation and degradation of these hormones over time in various burial environments is crucial.

The study has garnered attention from experts in the field. Nikolas Lemos, a professor of forensic medical sciences at Queen Mary University of London, described it as “a pioneering study… which has achieved a world-first.” He cautioned, however, that the small sample size—only two of the ten individuals were pregnant at death—means the findings should be viewed as proof of concept rather than a routine diagnostic tool.

Another expert, Alexander Comninos, a professor of endocrinology at Imperial College London, highlighted the research’s potential implications. “By understanding reproductive profiles of the past, this can provide insights into how these may have changed over time and perhaps glimpses of the future,” he stated. The ability to identify key hormones in bone could also stimulate further contemporary research in related fields.

The groundbreaking findings open new avenues for understanding the hormonal dimensions of life and death in ancient populations. As researchers continue to refine their methods, the implications for archaeology and historical understanding could be profound.