A seminar held by the Royal Thai College of Obstetricians and Gynaecologists Monday warned women against wearing underwear made from synthetic fabric because such material has poor ventilation when compared to cotton.

"Poor ventilation around women's private parts could lead to infections," said Dr Veeraphol Chandeeying of Prince of Songkhla University's Faculty of Medicine.

Veeraphol said common symptoms of infections such as leukorrhea include vaginal discharges of abnormal colour or with a foul smell.

Most women seeking treatment from gynaecologists were diagnosed with this type of infection, he said.

"One of the main causes is their underwear," he added.

Aside from choosing the right type of fabric, Veeraphol also emphasised that the underwear must be clean. After being washed, underwear should be left to dry in the sun, he said,

Dr Annop Jaisamran, of Chulalongkorn University's Faculty of Medicine, said infection could lead to inflammation.

"Although it is not life-threatening, it affects quality of life," he said.

He said some infections could also cause gonorrhoea. In the case of a prolonged viral infection, he said the risk of cancer also increased.

Annop said it was best for women to wash using clean water and to avoid tight pants or jeans.

"Avoid tight outfits or you risk getting a fungal infection. Choose underwear that will not cause irritation. With proper care, women won't need to visit a doctor about this problem," he said.