Rat pupGERLINDE METZ The history of a grandmother’s stressful environment during pregnancy can be passed on to her grandchildren, according to a study published today (August 7) in BMC Medicine. The daughters and granddaughters of female rats exposed to two types of stress per day during the equivalent of the human second trimester had shorter pregnancies of their own, and bore offspring that exhibited physiological and behavior changes. These changes could be the result of a microRNA (miRNA)-mediated mechanism, which may be epigenetically inherited across generations.
“One of the surprising findings of our study is that even if only the grandmother was stressed but not the mother, there were effects that persisted and even grew larger in the subsequent generations,” said study author Gerlinde Metz, a neuroscientist at the University of Lethbridge in Canada.
Metz and her colleagues used a rat model to study whether stress is a risk factor for preterm birth. A multifactorial condition, the causes of preterm birth are not known in about half of human cases.
The researchers stressed pregnant rats by restraining them for 20 minutes and, separately, making them swim for five minutes daily during days 12 to 18 of gestation.
Because the length of gestation was not changed in stressed compared to non-stressed rats ...
