Munich  - Extra-strong ultraviolet (UV) light rays are best avoided during pregnancy, according to an association of German doctors.

Pregnant women should pay particularly close attention to the duration and strength of UV rays in tanning studios, the BVF Professional Association of Gynaecologists advises.

Due to the extra hormones in their system, pregnant women sometimes report that their skin takes on a darker pigmentation. Additional UV light can increase the number of liver spots and freckles.

Additionally, sensitive skin can react with a sun allergy or an irritation. According to the group, pregnant women should stay in the shade when outside. That way, any dark pigmentation that builds up during pregnancy should fade after birth. (dpa)