A young, married couple has difficulties conceiving a baby, so after a while the wife consults her doctor, who recommends the minor of three possible operations.
The operation is performed, but a month later, she's still not pregnant, so she goes to see the doctor again. This time he recommends the medium operation, a somewhat more serious operation, but still not as complicated as the third alternative. But, there's still no result and another month later she's back in the doctors office, and this time she gets the big one. After having recovered in some weeks, the couple resumes normal marital activities, and this time they actually succeed in conceiving a baby.
Filled with joy, the young wife now sees the doctor for the regular examination during pregnancy and says, "We're so happy doctor, we're finally having a baby. But what was this third operation actually all about? The first two weren't that bad, but this last one I think must have been quite a job, I was dizzy for weeks after."
"Well," the doctor replies, "since the first two standard operations failed, we started suspecting your method rather than your ability, so I made a connection from your throat to your uterus."