Women may be more vulnerable yeast infections and sexually transmitted diseases during ovulation, according to a new study

The research was published in the journal of Leukocyte Biology.

Researchers noted that during ovulation the natural 'dip' in female immune response may decrease so that the sperm may fertilize an egg successfully.

"This could be an explanation why during ovulation females have more risk of being infected with sexual transmitted diseases like HIV or HPV," said Miguel Relloso, Ph.D., a researcher involved in the study.

Using animal study researchers found sex hormone estradiol decreased female immune response, thus increasing susceptibility to infection.

Estradiol is the most important form of estrogen found in the body. Most of it is made in and released from the ovaries, adrenal cortex, and the placenta, which forms during pregnancy to feed a developing baby, according to National Institutes of Health.

"This adaption which allows male sperm to survive long enough to fertilize an egg may also open the door for other types of infection" said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology.