The birth control pill can cause yeast infections because it affects the balance of hormones in the body causing larger amounts of estrogen which raises blood sugar levels and feeds the yeast. But it is true that other devices can also cause yeast infections in some women. There are now over forms of birth control that use hormones still but are not in the form of a pill, and these can cause yeast infections in some women for the same reasons.
Birth control devices like cervical caps and diaphragms have the potential for causing a yeast infection as they can trap moisture leading to bacteria or yeast being a possible problem. They need to be looked after properly and carefully after each use.
IUDs may also be a cause of candida overgrowth not because of the IUDs themselves but because often antibiotics are prescribed when they are initially inserted. Antibiotics cause yeast infections because they kill the good bacteria as well as the bad. Therefore to combat this problem take probiotic supplements like acidophilus to help maintain your body’s natural balance.
A quick mention here about condoms, though they are not exactly a ‘device’. Some woman find the material of some condoms causes their symptoms to worsen, and some condoms have a spermicide or lubricant added, which for some women can cause irritation and lead to a yeast infection.