'Parenthood' star Erika Christensen pregnant with first child

LOS ANGELES, April 1 (UPI) -- Erika Christensen and husband Cole Maness are expecting their first child.

The 33-year-old actress announced the news on social media before debuting her baby bump at the Los Angeles premiere of her HBO movie, Confirmation.

"This boy is getting a little sister. A human sister," the star captioned a photo with her puppy. "She'll make her first appearance tomorrow at #Confirmation."

"We're expecting!" she confirmed in a follow-up tweet Friday. "Very excited that our baby girl will be coming soon."

Christensen showed off her growing belly in a form-fitting sleeveless gown at the premiere. Sources told Us Weekly the actress joked about wearing "the tightest dress [she] can," adding she and Maness were "so excited" on the red carpet.

The former Parenthood star and Maness have been together since 2012 and married in September. Christensen largely keeps her private life out of the spotlight, but has previously made headlines for following Scientology.

Christensen is known for Traffic and Swimfan and playing Julia Braverman-Graham on NBC series Parenthood. She has since portrayed Betty Beaumontaine on Wicked City, and will play Shirley Wiegand in Confirmation.