The prayer is a way to highlight the dignity and sanctity of human life from the moment of conception. In fact, it will be read, for the first time, in several U.S parishes next Sunday to celebrate Mother's Day.
The blessing was first approved by American bishops back in 2008, but most recently, the Vatican gave it its final approval. The text can be downloaded at www.usccb.org. But one can also order the 43 page booklet, which is both in English and in Spanish.
The name of the prayer is "Rite for the Blessing of a Child in the Womb.” Among other things, it's meant to promote parent's special bond with their child, even before it's delivered into the world.