Species II (1998)

The Excursion expedition lands on Mars and Commander Patrick Ross becomes the first man to walk on the red planet. But as the expedition returns to Earth, soil samples thaw out and infect the crew. On Earth, Laura Baker has succeeded in creating Eve, a genetically modified version of Sil whose reproductive drive is now controllable. However Laura is soon shocked to find that there is another version of the alien creature on Earth. She reunites with Preston Lennox to track it down and they soon find that they are hunting Ross, who has been infected with species DNA. He is having sex with as many women as possible, causing them to instantaneously become pregnant and give birth to alien male children.