In case the couple the couple does not have a child, one can acquire progeny through mantras, provided one does the sadhana with full faith.

“Om devkisut govind vasudev jagatpite

Dehi ye taney Krishna tawamahem sharanam gata”

This mantra should be recited 3 lakh times continuosly.

Another tested mantra for being blessed with son

“Om kaleeng gopalveshdharya vasudevaye hoong phut swaha”

Recite the above mantra one lakh times and then perform homa with sugar, curd, ghee, rice and five types of dry fruits. Mix them with water and boil. We say khir in hindi. Before japa is started perform pooja of lord Krishna sitting inside the blooming flower of lotus. You will surely blessed with son. The couple should do this sadhana themselves. Hired people should be strictly avoided.

or

Certain specific tested remedy for birth of child for a barren lady or for having son

The Monday falling after the monthly period of a woman, the husband keep fast on Monday. The lady should go to lord Shiva’s temple. After performing pooja and offering water one seed of the shivlingi should be cleaned with water. Bring it home and wrap in old gur, which the lady should swallow. Repeat for 11 days. Keep fasts on Monday forever. No sex for 11 days. One will be blessed with son.