No matter how bad your guy’s sense of direction is, there’s a good chance his sperm knows exactly where to go and how to get there in a short matter of time.
Sperm is Fast… With a Bit of Help
Several studies have found it only takes between 1 and 5 minutes for sperm to reach the fallopian tubes (yes, that’s without crazy handstands!). It’s a team effort though. Research showed that outside the body, but in substances that resemble the inside of your reproductive tract, sperm moves at about 5mm/min. So they’re not that quick and they need some help.
Luckily, your uterus is willing to lend a helping hand! One of the layers of the uterus, the myometrium, contracts. These contractions cause sperm to get swept up and moved in the right direction. These contractions are always present, but they increase in intensity and occur more frequently as ovulation day approaches. It is somewhat like the contractions when you’re on your period. Except those contractions are much stronger, and of course, they move the other way around, DOWN instead of UP!
The sperm-moving contractions are very mild and you won’t even notice it’s happening.
Cool fact: We know that these contractions are regulated by hormones. When you’re in your fertile window, the contractions are more frequent and stronger compared to after ovulation, probably because their main purpose is to get sperm to the tubes in a timely manner.
Kunz, G., et al. 1996. Human Reproduction 11 (3): 627–632.
Mortimer and Swan. 1995. Human Reproduction 10 (12): 3178-3182.