Washington | Researchers led by an Indian-origin scientist have identified a cellular signal that could tell doctors when pregnant women are about to go into labour. Researchers found a cellular signal in the amniotic fluid around the foetus that builds up when a pregnant woman is about to go into labour.
The initiation of the birthing process is complex. Several body systems maintain pregnancy through a delicate balance altering this balance tends to promote labour, said lead author Ramkumar Menon, assistant professor at the University of Texas Medical Branch at Galveston in US.
For the study, researchers focused on telomeres, which are the parts of the DNA that protect genetic data while cells are dividing. These telomeres become shorter every time a cell divides, which hinders their ability to ensure that the new cells are identical to the parent cells. This shortening process is linked with the changes that take place in our bodies as we age.
Over time, the telomeres become too short for the cell to divide and they become senescent. We investigated whether the presence of senescent telomere fragments in the amniotic fluid around the foetus is linked with labour status, as we know that the telomeres continue to get shorter as the pregnancy progresses, Menon said. The researchers used amniotic fluid samples from the Nashville Birth Cohort Biobank of 50 women in labour and 51 women at the end of their pregnancy but not yet in labour.
They also acquired demographic information from patient interviews and medical information from their medical records. In addition, the team dissected foetal membranes from the placenta after babies were delivered at term. Menon said his team wanted to know what triggered a change in the delicate balance that had maintained a pregnancy. We began this study suspecting that the senescent cells cause oxidative stress-associated damages to the amniotic sac that create inflammation in the placenta, said Menon.
We know from previous studies that inflammation can alter the balance of the mother’s hormones in the uterus, triggering the labour process, he said. The researchers used telomere mimics, resembling those found in amniotic fluid, and conducted cellular analyses, finding more telomere fragments when a woman who was in labour compared to women who were at the end of their pregnancy but not yet in labour.
They found that as the foetus mature in the womb and nears term, placenta and other related tissues also age due to telomere fragmentation and eventual loss. These telomere fragments can increase sterile inflammation potentially signalling foetal maturity to trigger the process of labour and eventual delivery, Menon said.
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