Maybe Morning Sickness Is A Good Thing?

From NewSci: Morning sickness may be sign of a bright baby

Morning sickness, which affects most pregnant women, is thought to be a reaction to the hormones human chorionic gonadotropin and thyroxine, which are secreted at unusually high levels during pregnancy to maintain a healthy placenta. Now Nulman speculates that these hormones, which are higher in women who experience morning sickness, may protect the fetus's developing brain.