If you and the new parents share the same religion, then it is best to quote a saying from your inspirational book or a blessing that is commonly said for a new baby. It's also right to invoke the name of God in asking for blessings for the new family.
Writing down your prayer in a card before saying it is a beautiful keepsake for the parents-to-be. If will then be easier for the new parents to memorize the prayer through repetition over the little baby.
For example, if the parents are Christians, it is easy to search through the Bible or the internet to find verses that talk about children being God's gifts or that they are made by God himself. For example, the Psalms are a terrific source of many different verses that talk about God's gifts and the works of his hands.
A beautiful verse to quote is Psalm 92:4 says: “I sing for joy at the work of your hands.” You could tie this verse in to your feelings of happiness at learning your close friend or relative was expecting a new child, since in the Christian belief, all people are given life by God.
The Psalms are also a wonderful source of blessings for the new child. Psalm 121: 7-8 says, “The Lord will keep you from all harm – He will watch over your life; the Lord will watch over your coming and going both now and forever more.” You could also write a blessing of your own, just word it in a way that it speaks directly to the parents-to-be and the coming child, instead of to God. These are simply your heartfelt wishes for the new family.
A baby shower is the time that family and friends come together to support the new family and shower them with love and care, more than the little presents that are given. It's also a time that the ones that hold fast in their religion can see God's love in a more physical way and draw on that love and care for support.
Any close friend or relative would be the best person to ask to say the baby shower prayer. Any time during the baby shower is the best, whether before cutting into the cake to share with the others, before opening the presents or even afterward as a reminder for thanksgiving, or after the speeches are said to highlight the guests of honor. This is a time of rejoicing and God should be invited into their lives and future, as this Irish blessing does:
“Blessing for the Children”
“O Thou, to whom to love and be are one,
“hear my faith cry for them who are more
“Thine than mine.
“Give each of them what is best for each.
“I cannot tell what it is,
“But Thou knowest.
“I only ask Thou love them and keep them
“With the loving and keeping Thou didst
“Show to Mary's Son and Thine.”