First, it is important to understand exactly what the term means. Precum or pre-ejaculation fluid is what is produced by the male body during sexual intercourse. The fluid travels down the urethra and out of the tip of the male penis; the fluid helps clear a path for sperm which is released during ejaculation which contains the highest sperm concentration.
Pre-ejaculation is also referred to by terms such as precum or pre-seminal fluid. The chances of getting pregnant from precum are not high, but it can happen because the fluid may contain small amounts of live sperm. The fluid is not actually made with sperm but rather picks it up along the route to the tip of the penis, which means it could result in conception if it is deposited in the female's vagina.
The sperm in precum can be picked up from a previous ejaculation and travel with the fluid and may cause pregnancy. The best way to avoid sperm in precum is to have the male urinate after having an orgasm but prior to vaginal penetration. Using the withdrawal method for preventing pregnancy is not fool proof and many couples have found themselves pregnant even when trying to prevent it because of precum containing live sperm. Trying to avoid conception without ejaculating requires a male to know his own body very well and he has to know the precise moment he is going to release seminal fluid, otherwise there is a good chance of pregnancy.
For a couple that is trying to conceive, using precum as a gauge or method of trying is not reliable. There are more effective ways of conceiving and discontinuing birth control and making sure to time intercourse during ovulation are two of the most reliable ways to increase the odds. Some people are of the mistaken impression that precum contains no sperm, but this is not always true. When trying to get pregnant, precum has been known to result in pregnancy; if a couple has any questions it is a good idea to consult with their medical professional for further information.