I know a baby born with so much thick and preternaturally groomed hair, his family said he looked like one of the Kennedys. Conversely, many a newborn emerges Eisenhower-bald. Either way, most newborns lose whatever hair they were born with in the first three or four months of life.
But wait—there's no need to resort to babytoupee.com (yes, it's a real site). Unlike the normal cycles of adult hair growth, elevated hormone levels during pregnancy prolong the hair growth phase for fetus and mother. Then, after birth, hormone levels drop, causing many of the baby's hair follicles to enter the telogen phase, a resting stage. When the next growth phase begins, the new hair (sometimes a different color or texture) pushes out the old, and before you know it, you're looking at a lot of scalp (at least until the new hair's a bit longer).
Another type of baby baldness occurs when an infant tends to sleep on the same side of her head, causing bald patches. You can try adjusting her sleeping position and see if she'll tolerate it. If not, there's always the comb-over.
And Another Thing...
A 2006 Johns Hopkins University study found that pregnant women who experienced moderate to severe heartburn gave birth to children with average or above-average amounts of hair. Researchers believe that the same hormones that increase fetal hair growth also can relax the sphincter in the mother's esophagus, resulting in heartburn.
Adapted with permission from Why Babies Do That: Baffling Baby Behavior Explained, by Jennifer Margulis, published by Willow Creek Press. 2005 by Jennifer Margulis. All rights reserved.