London - Mothers who buy creams to get rid of stretch marks are wasting their money, scientists warned.
Most of the treatments have no basis in science, and no product on the market can repair the elastic skin fibre damaged in childbirth.
Up to 90 percent of mothers are left with stretch marks on their stomach, which are caused when deep layers of the skin are stretched or torn.
Moms who put on excess weight or have twins are more likely to get them, although some remain mark-free, even after having several babies.
Professor Frank Wang, of Michigan University in the US, advised women not to believe the hype when they see creams and ointments promising to prevent or reduce pregnancy stretch marks.
Dermatologists are still learning about what causes stretch marks in the first place – and skin stretching is not the only risk factor.
He said: “Most of the existing products aren’t based on solid scientific research.
“Very few to none of the items touted to prevent or fix stretch marks really work.” In the first study of its kind, which has been published in the British Journal of Dermatology, his researchers investigated what could be causing stretch marks at the molecular level.
Professor Wang has spent more than eight years researching the linear lesions – also known as striae gravidarum – which have not been widely studied.
He said: “Because stretch marks may compound the stress of new motherhood for many women, it’s important to learn more about them. Some women feel their self-esteem, quality of life and willingness to engage in certain activities are affected.”
An analysis of skin samples from 27 pregnant women with recent stretch marks compared stretched skin on the abdomen to less stretched skin on the hip, and found the network of elastic fibres in the lower layer of skin that creates new cells had been permanently damaged.
Elastic fibres help skin snap back into shape after stretching. Once the network is damaged, women are left with loose, scarred skin. Professor Wang said: “It may make more sense to focus on preserving the elastic fibres you have rather than repairing damaged ones.
“Regardless, it’s more complicated than just rubbing something on your stomach.”
Daily Mail