In theory the sperm could get up there but it is impossible to impregnate the baby. Firstly, the baby is in an ambiotic sack (kinda like a big bubble full of fluid that bursts when you're giving birth hence the saying 'waters breaking). Secondly, to get pregnant, you have to be ovulating in order to have an egg in your body that is fertile and ready for a sperm cell to fuse with and seeing you don't starting ovulating until the age of around 11 years+, it's pretty much impossible.