A bizarre side effect to pregnancy is that you don't lose any hair while you are carrying the baby. After giving birth, it is only a matter of time before you not only resume normal hair loss, but all of the hair that you didn't lose during pregnancy jumps ship as well. This can result in tumbleweeds of tresses blowing throughout your home.
Some women lose hair in clumps, which I can imagine is frightening. Mine didn't fall out in clumps, but I did lose a staggering amount after having F - way more than I lost with C and M. Further proof that every pregnancy is different.
Many pregnancy books discuss this topic, but they typically say something along the lines of "some increased hair loss is common in the few months after giving birth." That bit of information doesn't prepare you for pulling hair balls the size of a small woodland creature from your shower drain.
Sometimes you need the gory details to truly understand what is coming your way. So, there you go, information AND gross details.