What is a major concern regarding the use of sponges for contraception?

The major concern regarding the use of sponges for contraception is that they do not protect against sexually transmitted infections (STIs). The primary function of contraceptive sponges is to prevent pregnancy by releasing spermicide and creating a barrier against sperm reaching the uterus. However, unlike condoms, sponges lack the ability to block or reduce the transmission of STIs between partners. This limitation is significant as individuals engaging in sexual activity may be at risk of contracting or spreading infections without proper protection, which is a key consideration for sexual health.

The other options highlight either misunderstandings or irrelevant factors concerning the use of sponges. While sponges may be less accessible in some regions, this does not address their efficacy as a barrier method against infections. Additionally, sponges are not equipped to provide STI protection and can lead to misconceptions about their protective capabilities. Lastly, sponges do not have a hormonal component, so they do not cause hormonal imbalances, making this concern misplaced in the context of sponge use.