You've read all the baby books and diligently taken notes as your childbirth instructor gave you information on riding labor contractions with a combination of breathing, massage, position changes, and, possibly, pain medications. Despite all your preparation, your baby may still deliver some surprises on labor day, since classes, books, and even your dearest friends might not be willing to share some of the grittier realities of childbirth. Even some of the most common labor scenarios can come as a complete shock if you've never heard anyone mention them, so it is helpful to have some insider knowledge beforehand.
For starters you can expect to forget every single thing they showed you in childbirth class. In the throes of labor, your mind may go blank. Breathing? Labor positions? Huh? You might find yourself suddenly lying on your back and gripping the bed -- the last thing you ever imagined yourself doing during labor. To prepare for this, confirm that your labor partner knows the breathing techniques, has photos of the birthing positions you've talked about, and is armed with a list of your birth wishes in both best- and worst-case scenarios.
At some point during labor, your teeth might chatter. About half of women in labor complain of shivering and chattering teeth, even though their body temperatures are actually higher than normal. This is normal and nothing to worry about.