Tanning beds are not advised during pregnancy. First you want to avoid burns during pregnancy since they can lead to infection. Also, because they work on intense heat they dont want baby getting exposed to that intense of heat, that is why they will say to avoid hot tubs-saunas and even hot baths and showers. They want baby staying at a more even temperature.
skin cancer! thats the risk, in Australia they have made them illegal for under 18 to use them and they will be phased out for everyone in the next 3 yrs, they are extremely dangerous