Kourtney, 35, shot for her DuJour cover story during pregnancy last year. She and partner Scott Disick welcomed son Reign Aston in December.
During her shoot, sister Kim Kardashian and Disick both made cameos to show their support, reported E! Online.
"She does look quite amazing, I mean she's really got a glow to her, so I'm pretty proud of her," Disick could be seen saying in the video.