Hilaria and Alec Baldwin reportedly used a surrogate to give birth to their 6th child

• Multiple reports confirm that Hilaria and Alec Baldwin used a surrogate to welcome their new child.
• The couple welcomed baby Lucia in early March, but the news caught many people by surprise.
• Hilaria gave birth to the couple's fifth child, Eduardo, nearly six months ago.

Hilaria and Alec Baldwin welcomed their sixth child, Lucia, via surrogate, a source confirmed to People.

E! News also confirmed that the couple's new baby "arrived via surrogate."

Representatives for the couple did not respond to Insider's repeated requests for comment.

Hilaria first revealed the latest addition to their family in an Instagram post on March 1, which she captioned "7" along with a heart emoji.

A day later, the yoga instructor shared a close-up of the newborn, writing, "We are so in love with our daughter, Lucia. Just like your brothers and sisters, you are a dream come true."

Lucia follows shortly behind her older brother (the Baldwin's fifth child) Eduardo "Edu" Pao Lucas, who was born on September 8.

In addition to the newborn and Edu, Hilaria and Alec have four other children together: Romeo, 2; Leonardo, 4; Rafael, 5; and Carmen, 7. Alec also has a 25-year-old daughter, Ireland, with his ex-wife, Kim Basinger.

The timing of Lucia's birth caused many to speculate whether the Baldwins, who tied the knot in 2012, adopted her or used a surrogate.

New York Times reporter Katie Rosman wrote earlier this week on Twitter that when she asked if their newborn was adopted or if Hilaria was pregnant last year, a rep for the mother responded, "Not sharing!"

Fans zeroed in on the possibility of surrogacy, especially since Hilaria follows Alcea Surrogacy, a gestational surrogacy agency with office in Texas and New York, on Instagram.

It's worth noting that the Baldwins, who reside in New York City, likely didn't use a surrogate in New York State.

Paid surrogacy was just made legal in the state on February 15, giving people with infertility, as well as gay couples, single men, and others more options when it comes to building a family.

Previously, surrogacy - or carrying a child to whom you're not biologically related to term - was only allowed in the state if the surrogate wasn't paid. After New York's move, commercial surrogacy only remains prohibited in Michigan and Louisiana.