Heather Rae El Moussa wore a backless dress with a custom 'Baby El Moussa' chain to her gender reveal party

• Tarek and Heather Rae El Moussa had a gender reveal party on Sunday.
• Heather wore a white ILA dress with a custom "Baby El Moussa" chain on the back.
• The couple's son is due in January 2023.

Heather Rae El Moussa had fun with maternity fashion at her gender reveal party.

Heather, 34, and Tarek El Moussa, 40, are expecting their first child together. They announced the news on July 13, revealing that they got pregnant naturally while in the process of IVF. 

The El Moussas had a gender reveal party on Sunday planned by Sonia Studios, where they found out they're having a boy. Their son is due in January.

Heather embraced the party as an opportunity to have fun with maternity fashion, wearing an ILA slip dress in a look styled by Caitlin Jaymes.

The white dress had an ankle-length skirt, halter neckline, and floral detailing on the collar.  

The dress was backless, with a crystal chain hanging above the skirt. Letters hung from the chain, spelling out "Baby El Moussa." 

Heather wore her hair in an updo, letting the fun detailing shine.

Heather previously told People she was looking forward to wearing fun maternity looks, particularly because she had been hiding the pregnancy.

"I'm so excited to announce it. I've been having to hide it at the gym and at events and going out places," she told People. "I'm used to wearing tight clothing, I'm used to wearing tiny clothing, and having to hide it, it's just been very, very challenging."

"I can't wait to start wearing my tight dresses, my cute maternity stuff, and show it off rather than hiding it," she went on to tell the outlet.