Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
There is no objection to doing so. However, some Fuqaha (Islamic jurisprudents) are of the view that it is disliked to organize a celebration ceremony on the occasion of the birth of a child, (Aqeeqa) and this is the view of the Maliki school of thought. But some other Fuqaha said that it is permissible.
Ibn Qudama said in Al-Mughni: "the ruling about inviting people for circumcision and other invitations other than walimah (marriage banquet), is that it is desirable as it is offering food."
The other evidence is what Imam Muslim and Abu Dawud reported that Ibn Omar narrated that the Prophet (Sallallahu Alaihi wa Sallam) said: "If any one amongst yourselves is invited, he has to accept the invitation, whether it is at the occasion of a marriage or the like."
Therefore, there is no harm Insha Allah in the organization of this walimah, no harm to attending it and making Du'a for the parents of the new born child.
Imam Al-Nawawi said in Al-Adhkar: "It is desirable to wish-well for the new born child. The people of our school of thought said: "It is also desirable to wish-well for the new born child with what Al-Hasan al-Basri, may Allah have mercy on him, used to say while teaching a person the wording of the well-wishing "May Allah bestow His blessings on your new born baby. May Allah guide you to thank Him. May this child become an adult, and be obedient to you."
And it is desirable to respond to the well-wisher saying: "May Allah blesses you", "May Allah rewards you", "and May Allah rewards you with the same"…
To conclude, we draw the attention of the questioner that your supplication for the parent of the newly born baby should not be said collectively, so that people would not think that supplicating in this manner is Sunnah, but every one of you should supplicate for the parent of the child individually when wishing well for the child.