Which will reduce the appearance of stretch marks, UV or Spray tanning?

After my baby of course I resulted in having stretch marks on my stomach and on my thighs.The stretch marks on my stomach are light but my thighs are pink.I heard that tanning will even the skin and will reduce the appearance of the stretch marks.So my question is which is more effective the UV or Spray Tanning?Please let me know what are your answers, I really wan to wear shorts this summer. Thank you..