Wikipedia
Simantonnayana
Simantonnayana (literally: parting the hair) is the third of the 16 saṃskāras ( sacraments, rites of passage) in the ancient texts of Hinduism. It is observed in the last trimester of pregnancy to wish for safe delivery and is similar to a baby shower.
The authorities are not unanimous whether this saṃskāra should be performed for the first child or it should be performed for every child.