Myolie Wu is pregnant with her third child, but her husband would like to keep the gender under wraps for now.

The Hong Kong actress, who has two sons - Brendan, three, and Ryan, 1½ years old - with businessman husband Philip Lee, announced on Christmas Day that she is with child again.

On Thursday (Jan 7), Mr Lee posted on social media a photo of their family of four in red Christmas sweaters, with him and Wu holding a red baby garment between them.

He wrote: "Reunited. And this time we are five....what do you think? Girl or boy?"

Wu, 41, had returned from China in December after taking part in acting reality series Everybody Stand By 2, in which she emerged the winner.

Mr Lee's post sparked guesses from celebrities and fans, with actress Linda Chung even guessing that Wu is carrying twins.

Several fans guessed that it would be a girl as they said the baby garment they were holding looked like that of a dress.

Mr Lee saw the comments, and later edited his post: "The top is a unisex onesie. It's supposed to be different from big brothers' tops."

Wu, who is known for roles in TVB dramas such as Triumph In The Skies (2003), Wars Of In-Laws (2005) and To Grow With Love (2006), has so far not commented under her husband's post.

However, she told the Hong Kong media while filming an advertisement last week that she is six months pregnant. She did not disclose the gender of the baby, but said her husband hoped that it would be a girl.