Sacral dimple is common cutaneous finding in new born.
It may be normal or may be associated with some abnormality. If the skin in the dimple is intact then chances of deeper involvement is less. Presence of hair in the dimple may indicate some problem. It also depends upon the distance of dimple from anus, the farther the dimple chances of associated abnormality is more. As there is also hair tuft in the dimple, I would suggest you to consult your physician and get a ultrasound
examination of lumbosacral region done to rule out any abnormality. Even if chance of abnormality is less a normal test will decrease your anxiety