Molly had a ton of hair at birth. I don't think she's lost a ton. For a long time I was really meticulous about inspecting the hairbrush after a bath for any precious stray hairs. I don't know if I missed it or if she kept the same amount and her head just grew contributing to her thinned-out appearance. The back of her head is the exception. I suppose it's a fair trade for the safety of the 'back to sleep' campaign. I also think more tummy time is in order.