Some days ago a fellow priest asked me if I had a prayer for a married couple who wanted to have children. I checked my four volume Book of Needs, my smaller Book of Needs, my Greek Mikron Euchologion, and then searched online. There was no such prayer to be found. I then asked an online clergy brotherhood forum for help. Much discussion was had on the value of pilgrimages, St. Irene Chrysovalantou, and the relic of the belt (zone, cincture) of the Theotokos. Eventually, someone mentioned that the Priest's Service Book (Mikron Euchologion, Agiasmatarion) by Fr. Evagoras Constantinides of blessed memory has such a prayer. He supplied me with a photo of the page and I was able to pass it on. Sadly, I am unable to find a hard copy of this book and Holy Cross Bookstore no longer carries it.
Pastorally, I would personally advise a couple to make a pilgrimage and send them off with this prayer. God willing, this prayer will be useful to priests and couples praying for the blessing of a child.
Yet, on many occasions, faithful couples like Abraham and Sara, Jacob and Rachel, Zacharias and Elizabeth, and Joachim and Anna were without children. But when they came to you in prayer and supplication, you responded mercifully to them, answered their prayers, and rewarded their patience and trust in you with one or more children.
In like manner, your servants [Name] and [Name] who were joined in matrimony in your holy name, O Lord, in order to fulfill your will, have not as yet been blessed with child. Therefore, with profound humility and utmost faith and trust in you, the pray to you and supplicate you and ask of you, it it be your will, to be gracious and merciful to them, to remove their pain and sorrow, and to bless them with fair offspring at a time pleasing to you.
Yes, Lord our God, accept the petitions of me, your unworthy servant, and bring to your servants [Name] and [Name] joy and peace by granting them their request and blessing them with with a child.
For you alone are merciful and compassionate, and to you we ascribe glory and thanksgiving and worship, to the Father and to the Son, and to the Holy Spirit, now and ever and to the ages of ages.