Scientists have made significant progress in testing ancient human remains for hormones associated with pregnancy, which could enable archaeologists to ascertain whether a woman was pregnant or had recently given birth at her time of death. This breakthrough was detailed in a study published on October 2 in the Journal of Archaeological Science.
The research team identified vital reproductive hormones—estrogen, progesterone, and testosterone—in the hard tissues of skeletons that date back as far as 1,000 years. Lead author Aimée Barlow, an archaeologist at the University of Sheffield in northern England, stated, “We found a “hormone archive” in skeletons and teeth.” Barlow emphasized that this discovery marks the first instance of detecting these specific hormones in dental structures and that progesterone had never before been measured in human bone tissue.
Detecting signs of pregnancy in ancient remains has historically been challenging. Scientists had assumed that the inorganic nature of hard tissues would preclude the preservation or detection of such proteins. However, Barlow decided to employ enzyme-linked immunosorbent assay (ELISA) on samples from ten skeletons, comprised of seven females and three males, spanning from the first to the 19th centuries. This technique is utilized to identify and quantify certain peptide and protein molecules, including progesterone, which is a crucial biomarker for pregnancy.
The results indicated that estrogen, progesterone, and testosterone were present in samples from bone and various dental structures, including dentin and enamel. “High progesterone levels in dental structures and calculus, the presence of estrogen in bone, and a lack of testosterone in hard tissues were consistent with pregnancy at the time of death,” the authors noted in their study.
This research highlights the potential of the ELISA method for exploring reproductive histories in ancient populations. Barlow noted that demonstrating that hormones can be preserved in skeletal remains could eventually enable researchers to uncover when a woman first became pregnant, the occurrence of pregnancy loss, and the intervals between births, especially in historical contexts lacking written records.
However, Barlow acknowledged that further exploration is needed to refine this technique for ancient remains. This includes establishing baseline hormone levels in skeletal tissues through extensive studies that also involve living individuals with comprehensive medical histories. “We also need to understand the fundamental science behind how these hormones are integrated into and stored in different tissues,” she added.
Experts in the field are recognizing the significance of this research. Nikolas Lemos, a professor of forensic medical sciences at Queen Mary University of London, commented on the study”s pioneering nature, stating it represents a world-first. He cautioned that the sample size was limited, with only two of the individuals being pregnant at the time of death, suggesting the need for further testing and validation of the ELISA method.
Alexander Comninos, a professor of endocrinology at Imperial College London, described the findings as “fascinating,” pointing out that they could provide insights into the reproductive profiles of past populations and how these may have evolved over time.
