Scientists have confirmed the existence of the ‘pregnancy waddle'.

According to a team from Japan, a baby bump changes the way women walk, even as early as the first trimester.

The scientists used 3D motion capture technology to create a biomechanical model of pregnant women. This allowed them to see how women adjust their movements in everyday life, such as getting up from a chair and changing direction while walking.

They pointed out that accidental falls cause 10-25% of trauma injuries during pregnancy and a pregnant woman has the same risk of falling as a 70-year-old woman.

"Prior to our study, there were almost no theory-supported models of the movement of pregnant women. This model is just the start of our goal of contributing to a safe and comfortable life before and after childbirth for pregnant women," the scientists from Hiroshima University said.

Eight pregnant women were brought into the research laboratory at three different times during pregnancy, as well as seven women who were not pregnant. Infrared cameras with 3D motion capture were used to record the women's movements. This information was then used to create virtual models to represent the average pregnant woman.

The results verified the existence of the so-called ‘pregnancy waddle' and found that even during the first trimester, pregnant women's centre of mass is further forward. This means they lean backwards when standing and they bend their hips less when walking.

This combination, the scientists said, can cause a pregnant woman to trip and lose her balance more easily.

They pointed out that computer models like this allow them to test various scenarios without putting any of the participants at risk.

"We want to find the ideal way for new mothers to carry their baby, what exercises are most effective to return to non-pregnant fitness, and what physical postures are best for work in the home or office. Now that we have the appropriate data, we hope to apply our model and make it possible to problem-solve these concerns of daily life," the team added.

Details of these findings are published in the journal, Applied Ergonomics.