Donald Trump Jr. slammed talk show host Chelsea Handler's post Monday where she had mocked his brother Eric Trump and wife Lara Trump's announcement about their first child. Lara Trump is expected to give birth to a boy in September.

"The liberal elite’s real hatred is hopefully starting to be apparent to mainstream America," Donald Trump Jr. wrote in a lengthy Facebook message in response to Handler's post on Twitter.

"Attacking the announcement of someone’s first pregnancy would seem below the belt to most, but sadly that’s no longer the case. So much for the party of science," Donald Trump Jr. wrote on Facebook.

After the announcement of Lara's pregnancy on Monday, Handler mocked and said: "Another person with those jeans [sic]. Let’s hope for a girl." Instead of writing "genes," Handler wrote "jeans" and Donald Trump Jr. was quick to spot it and slammed her for the tweet. He also corrected her on Twitter.

Eric Trump also responded to Handler on Twitter and mentioned that it's a boy.

The child would be President Donald Trump's ninth grandchild. Eric Trump made the announcement on Instagram saying: "It's been an amazing year. We are blessed!"

Lara Trump spoke about her pregnancy to People and said that she had a hard time during her first trimester. "It surprised me, because I’m a very active person, and until the fatigue hit, I didn’t believe it would actually happen to me," she said.

The president retweeted Eric Trump's post on Twitter and congratulated the couple.

Donald Trump has eight other grandchildren. Donald Trump Jr. and his wife, Vanessa, have five kids namely Kai, 9; Spencer, 4; Donald III, 8; Tristan, 5; and Chloe, 2. Ivanka Trump and Jared Kushner have three children, Arabella, 5; Joseph, 3; and Theodore, who will turn 1 next week.

Eric Trump and Lara got married in October 2014. The couple got engaged on July 4, 2013, after dating for five years.