Lanugo is the hair that covers the body of some newborns. Lanugo may look like white or dark hair, or it may not have any. Lanugo is very thin, soft, usually unpigmented, downy hair that is sometimes found on the body. Lanugo: Downy hair on the body of a fetus or newborn baby. Lanugo begins to grow around weeks 14-16 of your pregnancy. Lanugo is the name for the soft, downy, unpigmented hair that covers Baby's body beginning in about the fifth month of pregnancy.