Yale School of Medicine researcher, Dr Hugh Taylor co-authored the latest study to probe the impact of cellphone exposure on pregnancies.
"We had pregnant mice in cages and we just simply put a cellphone on top of the cage. In half the mice, the cellphone was active and in half of the ... Cages the cellphone was turned off so it wasn't transmitting a signal at all," Taylor said.
Researchers allowed the mice to give birth and waited until offspring were young adults before behaviours were tested, the 'Daily Mail' reported.
"The mice exposed to cellphones were more active. Their memory was slightly decreased ... These mice were basically bouncing off the walls and didn't have a care in the world," Taylor said.
The study shows there is a "biological basis" to suggest cellphone exposure can impact pregnancies, said Taylor.
Patients should be cautious with devices and recommends pregnant women hold phones away from their body, he said.
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The World Health Organisation's cancer arm, in 2011, said cellphones could cause cancer and called for more research, it said.