Alec and Hilaria Baldwin welcome baby No. 4

See the sweet first picture!

Before heading to the hospital on Thursday, Hilaria shared a photo of herself dressed in sweats and slippers. "Earlier this morning...wish me luck. Bye bye baby bump," she wrote.

The baby, whose name has not yet been revealed, joins 4-year-old sister Carmen and brothers Rafael, 2, and Leonardo, 1.

Alec also a 22-year-old daughter, Ireland, with ex-wife Kim Bassinger.

Hilaria and Alec married in 2012 after meeting one year prior at Pure Food and Wine, a restaurant in New York, according to The New York Times.

“I was standing near the door with my friends when he walked up and took my hand and said, ‘I must know you,’" Hilaria told The Times.