Some hormonal changes early in pregnancy can lead to a delayed onset of puberty in both birth and adoptive daughters in mice, an Otago University researcher says.
Researcher Caroline Larsen and her co-workers found that mice with induced low levels of prolactin in early pregnancy displayed substantial anxiety after theygave birth.
She told a conference in Washington the researchers, who also noted that daughters had delayed onset of puberty, tried to find what was causing that.
To test their theories, daughters of female mice made anxious by low prolactin were raised either by their birth mother or by a mouse who was not anxious.
Another group consisted of daughters of ``non-anxious' mice, and these mice were raised by either a control mother or an anxious mother.
"Remarkably, puberty was still delayed even if the daughters of anxious mothers were raised by non-anxious mice," Dr Larsen said.
"And delayed puberty also occurred in daughters born to non-anxious mothers who were raised by anxious mothers."
This showed hormonal changes in early pregnancy, as well as changes in maternal behaviour caused by these hormone changes, could alter brain development in the offspring and delay puberty, Dr Larsen said.
The finding, with further study, may translate to people.
"There is growing evidence that untreated anxiety disorder during pregnancy may contribute to premature birth and also can have major and lasting adverse effects on the infant's development and behaviour.
"Finding the hormonal mechanisms that trigger the timing of puberty in mice may help identify potential targets for the prevention and treatment of delayed or early puberty in humans," she said.
Late puberty in humans is linked to shortened height and psychological problems that can persist into adulthood.
