There are many beautiful and helpful prayers in the MOTHERS’ MANUAL by A. Francis Coomes , SJ
You can see it here:
A prayer that would be of interest to you is on p. 12
To Have A Child
Mother of Christ, you know, as no other mother can, the high dignity of motherhood. You know how immensely great is the privilege to call into this world a tiny soul destined to praise God forever in heaven.
This is the privilege I now seek
Confidently I beg you to assist me, for I know that motherhood is so precious in your sight. And confidently, too, I hope for this blessing through your divine Son, since Jesus is the lover of the children and has said that we should allow them to come to Him.
It is for this blessing that I beg you to join to my petitions you own holy intercession, that I might priveleged to bring to Jesus a little one such as He may bless it, that He may also bless me, also, in my motherhood, and that He may then make us both grow in the wonders of His divine life.
Mother of Mothers
Pray for me!
God bless and also pray to Saint Gerard, who is the Patron of mothers!