Drawing a molecular blueprint of labour
The intricate process of childbirth triggers far-reaching changes throughout a mother's and baby's body. To shed light on the complex biological changes, Nepean Hospital researchers have compiled a world-first ‘multi-organ transcriptomic atlas’ of labour – a map to understand the molecular transformations that occur during one of life’s most precious and personal experiences.
New findings, published in leading scientific journal, Clinical and Translational Medicine, analysing data from 16 different studies and nearly 400 samples, examined the gene activity of women who were in labour and those who were not in labour.
Six key areas of the human body were analysed – the mother’s blood, fat tissue (both under the skin and around organs), placenta, uterus muscle and the baby’s umbilical cord blood. By examining which genes were switched on or off in these different areas, researchers were able to identify consistent patterns and pathways that represent characteristics of labour.
Nepean Hospital Clinical Director for Women and Children’s Health, and author of the study, Professor Ralph Nanan says the transcriptomic atlas provides a valuable new framework for understanding the complex molecular events that define labour.
"For the first time, we've been able to look across multiple organ systems in both the mother and the baby simultaneously to see the coordinated changes that occur," explains Ralph.
One of the most striking findings was the widespread activation of the mother's immune system. Across most of the maternal tissues examined, researchers observed a surge in TNF signalling – a key inflammatory pathway.
"We found that the mother's body mounts a significant immune response during labour. This could be a crucial mechanism to prepare her for the physical demands of childbirth and to protect against potential infections during and after delivery," says Ralph.
In stark contrast to the mother's heightened inflammatory state, baby’s umbilical cord blood revealed a surprisingly opposite trend - an increase in TGFβ signalling – a pathway associated in the suppression of inflammation.
“The baby’s response was most intriguing. The activation of anti-inflammatory signals suggests a protective mechanism, perhaps to buffer a newborn against the stresses of birth and the transition to life outside the womb."
Researchers also explored factors that might influence these changes during labour. They discovered that the increase in TNF signalling in the mother's uterus happened consistently, whether it was the first baby or not, even with preterm birth or pregnancy with smoking history, and that these inflammatory signals gradually increased as labour went on.
“The study provides novel insights into the choreography of molecular changes occurring in both mother and baby during labour and opens up exciting avenues for future research aimed at improving our understanding of normal and complicated births,” explains Ralph.
Full findings from the study are available to view online in journal, Clinical and Translational Medicine.