Apparently I kept the immortal ichor from Olympus, which we're guessing either healed some of the Blight damage or reversed some of its effects. The Blight is still present, but so is the ichor.

[As for Riddick's question:][Takes the print-out of the sonogram and passes it to him, pointing out the blurry features.] That's the head. These are the legs, and that's one of the arms.

[Hesitates, then adds:] Tachibana also offered to work on something to keep the infant safe from the Blight while in my womb. To make sure there's no chance of infection.