The Gone Girl star has given birth to a baby boy after a difficult pregnancy, according to

She recently told Fit Pregnancy magazine, "I felt tired and sick and in a fog, like an extreme hangover, until about week 16."

Wilson told the publication she was delighted when she discovered her first child would be a boy, explaining, "Having lost my mom, and having had such a close mother-daughter relationship, I felt, like, somehow I wasn't ready for a girl. I felt like the universe is letting me try this out with a boy first."

Wilson and Caspe are already planning ahead to add to their brood - the former Saturday Night Live star says, "We both come from two-kid families and I can't imagine going through life without a sibling."

The couple wed last year (14).