Which gland can best be called a temporary gland, Thymus or Placenta?

Both thymus and placenta are temporary glands. Thymus is largest in the foetus and  increases till puberty, after which it atrophies. Placenta is produced only during pregnancy and is expelled out of the body with the foetus.
But, if to select one between these two, placenta can best be called a temporary gland because:

• It is not present at time of birth
• It is present for a comparatively shorter time span (9 months) as compared to thymus (which is present till some time after puberty).
• It is found in females only and is completely absent in males.