I too remember being horrified when I first heard about this. Unfortunately, it
has become more of an urban legend than a real concern. While it is indeed a
theoretical danger, I have never been able to locate a confirmed case in the
medical literature, except in cases of pregnancy.
If you were to blow air very strongly into the vagina, with your lips pressed
tightly against the vulva (thus preventing escape of the air), it is
theoretically possible that you could create what is known as an air
embolus. This is a form of embolism, where an air bubble blocks the passage
of blood in an artery or vein. In severe cases, if blood flow is completely
obstructed, the tissue in that area would die. If the embolus were to travel
up to the heart or lungs, it would indeed be possible to die. You should know
that when a woman is pregnant, and her cervix begins to dilate, she is more
likely to suffer an embolism. In extremely rare cases, this has even been
reported to occur from intercourse.
In the days before abortion was legal, many women used to die each year from
embolisms created by the insertion of instruments into the uterus. So, yes, you
can definitely die from an air embolus, but the question is how likely one is
to be created from blowing air into the vagina.
I think it is pretty clear that normal, run-of-the-mill oral sex carries no
risk. Even blowing lightly onto the vagina is perfectly fine. I would,
however, avoid blowing strongly into the vagina, especially if your partner
is pregnant. Otherwise, there is really nothing to worry about -- but I'm
glad you asked.
