Congratulating new parents
بَارَكَ اللَّهُ لَكَ فِي الْمَوْهُوبِ لَكَ، وَشَكَرْتَ الْوَاهِبَ، وَبَلَغَ أَشُدَّهُ، وَرُزِقْتَ بِرَّهُ
Baarakallaahu laka fil-mawhoobi laka, wa shakartal-waahiba, wa balagha 'ashuddahu, wa ruzigta birrahu. The reply of the person being congratulated is to say: Baarakallahu laka wa baaraka 'alayka, wa jazaakallaahu khayran, wa razaqakallaahu mithlahu, wa 'ajzala thawaabaka.
May Allah bless you in what He has given you, may you give thanks to the Giver, may the child reach maturity, and may you be granted his dutifulness.