Researchers from the University of Sheffield and University College London have uncovered biochemical traces of pregnancy in centuries-old human skeletons, after detecting key sex-steroid hormones preserved in bones, teeth and dental calculus.
The breakthrough offers the first potential method for reliably identifying pregnancy in individuals who lived hundreds to thousands of years ago — opening a new scientific window into maternal health, fertility and women’s lived experiences in the past.
Scientists found measurable levels of oestrogen, progesterone and testosterone in skeletal tissues from individuals dating between the 1st and 19th centuries CE, using a new extraction and detection approach based on enzyme-linked immunosorbent assay (ELISA).
The ELISA method is able to detect and quantify sex steroid hormones in human hard tissues (such as bones, teeth and dental calculus), as these tissues survive considerably better, and are recovered more frequently than hair and soft tissues, in the archaeological record.
Key findings
- Researchers analysed samples from 10 archaeologically recovered individuals.
- Oestrogen, progesterone and testosterone concentrations were measurable in bone, dentine, enamel, and root samples, whereas only progesterone and testosterone were detected in dental calculus.
- In one woman who was known to have been pregnant at the time of death, progesterone levels were substantially elevated.
- Findings demonstrate the feasibility of reconstructing aspects of reproductive life for people who lived centuries ago, directly from skeletal remains.
Transforming the study of pregnancy in the past
Archaeologists have long struggled to identify pregnancy in historical skeletal material. Fetal remains are often too fragile to survive, and soft tissues disappear entirely. Pregnancy has remained largely invisible in the archaeological archive, which has left a huge gap in the historical narrative.
This new method could enable researchers to investigate the reproductive histories of women in the past using archaeological human remains, substantially improving the visibility of pregnant individuals and illuminating the reproductive histories of past populations.
For women throughout history, the experience of pregnancy, pregnancy loss and childbirth is life-changing, but it leaves almost no trace archaeologically. The human skeleton holds a record of life, and now we know that the skeleton can act as a hormonal archive. With further development, this method will significantly enhance our ability to observe and study pregnancy in the archaeological record, giving voice to the untold experiences of women in the past.
Dr Aimée Barlow
Lead Author, University of Sheffield
Funding
This work was supported by the Arts & Humanities Research Council (grant number AH/R012733/1) through the White Rose College of the Arts & Humanities. This study was also supported by the Department of Archaeology, University of Sheffield, and the British Association for Biological Anthropology and Osteoarchaeology.
For the full breakdown of Aimee Barlow’s research, including the methodology and results, read Aimee’s article written for the Journal of Archaeological Science.