Stress during pregnancy can be passed down through generations

lab rats

To better understand problems during pregnancies today, we should look to the experiences of our ancestors, research published in the open access journal BMC Medicine suggests. Scientists investigating pregnancies in four generations of rats show that inherited epigenetic effects of stress could affect pregnancies for generations.

Researchers from the University of Lethbridge in Canada wanted to investigate how preterm births are influenced by . Preterm birth is one of the leading causes of neonatal death and can lead to health problems later in life. They examined the length of pregnancies in because in general there is very little variation between them.

A first generation of rats were subjected to stress late in pregnancy. The following two generations were then split into two groups that were either stressed or not stressed. The daughters of stressed rats had shorter pregnancies than the daughters of those who had not been. Remarkably, the grand-daughters of stressed rats had shorter pregnancies, even if their mothers had not been stressed.

As well as shorter pregnancies, the rats whose grandmothers and mothers experienced stress displayed higher glucose levels than the control group. In addition, rats whose grandmothers or mothers who were stressed weighed less.

Gerlinde Metz, senior author of the article, says: "We show that stress across generations becomes powerful enough to shorten pregnancy length in rats and induce hallmark features of human . A surprising finding was that mild to moderate stress during pregnancy had a compounding effect across generations. Thus, the grew larger with each generation."

The researchers believe that these changes are due to epigenetics - the arrangement and expression of our genes. In most cases this refers to DNA methylation of the nucleotide base pairs. In this study the researchers believe the epigenetic changes are due to microRNA (miRNA) - non-coding RNA molecules that play a role in regulating gene expression.

Gerlinde Metz says: "Previous epigenetic studies have mainly focused on inheritance of DNA methylation signatures. What we didn't know was whether microRNAs, which are important biomarkers of human disease, can be generated by experiences and inherited across generations. We have now shown that maternal stress can generate miRNA modifications with effects across several . I think this is an interesting feature of our manuscript."

Further work needs to be done to understand the mechanisms that generate these epigenetic signatures and how they are passed down from generation to generation. With more knowledge of these mechanisms it may be possible to predict and prevent preterm pregnancy but also other diseases.

Gerlinde Metz says: "Preterm births can be caused by many factors, in our study we provide new insights into how stress in our mothers, grandmothers and beyond could influence our risk for pregnancy and childbirth complications. The findings have implications outside of , in that they suggest that the causes of many complex diseases could be rooted in the experiences of our ancestors. When we better understand the mechanisms of inherited epigenetic signatures, we can predict disease risk and potentially reduce the future risk of illness."

Explore further

Transmitting stress response patterns across generations

More information: Ancestral Exposure to Stress Epigenetically Programs Preterm Birth Risk and Adverse Maternal and Newborn Outcomes Youli Yao, Alexandra M Robinson, Fabiola CR Zucchi, Jerrah C Robbins, Olena Babenko, Olga Kovalchuk, Igor Kovalchuk, David M Olson and Gerlinde AS Metz BMC Medicine 2014, 12:121.
Journal information: BMC Medicine

Provided by BioMed Central
Citation: Stress during pregnancy can be passed down through generations (2014, August 7) retrieved 14 October 2019 from
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Aug 08, 2014
Excerpt: "In this study the researchers believe the epigenetic changes are due to microRNA (miRNA) - non-coding RNA molecules that play a role in regulating gene expression."

My comment: Nutrient stress and social stress act at the same level of cell type differentiation (i.e., amino acid substitutions). " Physical proof of species diversity links ecological variations from nutritional epigenetics to 1) biophysically constrained protein folding via 2) atomic level changes in base pairs (i.e., the nucleotides of DNA); 3) amino acid substitutions; 4) changes in the miRNA/mRNA balance; 5) the metabolism of nutrients to species-specific pheromones that 6) control the physiology of reproduction, and...."

Nutrient-dependent pheromone-controlled ecological adaptations: from atoms to ecosystems

Aug 08, 2014
cont. "... 7) chromosomal rearrangements that link the reciprocity of these interactions to the morphological and behavioral phenotypes manifested in species diversity. Across-species examples of biologically plausible ecologically validated cause and effect link the physical proof from conserved molecular mechanisms of DNA uptake that extends these representations of nutrient-dependent epigenetic effects to differences in pheromone-controlled morphological and behavioral human phenotypes."

No matter how many reports with experimental evidence that attests to the facts stated above, evolutionary theorists refuse to examine the biological facts. Most theorists already know that biological facts refute the pseudoscientific nonsense of their ridiculous theories, but few will admit it.

Aug 08, 2014
cont. Only a few molecular biologists have come forward with attacks on the pseudoscientific nonsense of evolutionary theory. Reports like this one will embolden other serious scientists and encourage more attacks on ridiculous theories and "Just-So" stories based on the ignorance of a gene-centric view.

See for example: Starvation-Induced Transgenerational Inheritance of Small RNAs in C. elegans http://www.cell.c...)00806-X

It substantiates their approach: "Our principle aim in the lab is to attack scientific dogmas. Mainly, we aim to use powerful genetic tools to discover novel biological principles by which RNA affects formation and inheritance of complex traits."

See also: Nutrient-dependent/pheromone-controlled adaptive evolution: a model
"The role of the microRNA/messenger RNA balance... in adaptive evolution will certainly be discussed in published works..

Aug 11, 2014

Modern science: http://www.scienc...1100010X

The vomeronasal organ (the pheromone receptor organ) is thus nonfunctional in human adults. Other decisive arguments back up this conclusion. The genes coding for V1R-type receptor proteins are mostly deactivated by mutation: only five sequences remain in the human genome (whereas mice have more than 180!); the same is true for those coding for V2R-type receptor proteins. Moreover, the genes coding for the trpc2 channels, essential to vomeronasal neuron activation, are again pseudogenes unable to give rise to functional ion channels. These features are shared by New World monkeys and marine mammals. Finally, on histologic examination of the olfactory bulbs in humans and New World monkeys, the accessory olfactory bulbs are found to be absent

Thus JVK - spammer James V Kohl is a swindler. The product you peddle, "scent of Eros" is a scam.

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