Like most forms of sexual activity, oral sex creates a risk of contracting sexually transmitted infections (STIs/STDs).
However, the transmission risk for oral sex, especially HIV transmission, is significantly lower than for vaginal or anal sex., meaning to suck.
The results were consistent with the fact that semen contains TGF-β1, the exchange of which between partners having a causal reduction in risk of pre-eclampsia caused by an immunological reaction.
It is worth noting that fellatio is not the only viable mechanism for the transmission of TGF-β1. Semen ingestion has had central importance in some cultures around the world.
Brushing the teeth, flossing, undergoing dental work soon before or after giving fellatio can also increase the risk of transmission, because all of these activities can cause small scratches in the lining of the mouth.
Such contact can also lead to more mundane infections from common bacteria and viruses found in, around and secreted from the genital regions.
Clinical research has tentatively linked fellatio with immune modulation, indicating it may reduce the chance of complications during pregnancy.
It may be that "few women praise the taste" of semen.The study found that 36 percent of the cancer patients had HPV compared to only 1 percent of the healthy control group.A 2007 study suggested a correlation between oral sex and throat cancer.Different people have different sensitivities to the reflex, but some people learn to suppress the reflex.Deep-throating is an act in which a man's partner takes the entire erect penis deep into their mouth, in such a way as to enter their throat.