prajastvam
su-prajastvam — the most beautiful son;
SB 5.4.4
su-prajastvam — having ten thousand well-behaved sons;
SB 6.5.23
su-prajāstvam — which insures good progeny;
SB 6.19.24
su-prajāstvam — a very nice son;
SB 9.1.20