Hilaria Baldwin Reveals Son Rafael, 6, Broke His Arm 'Really Badly': 'So Heartbreaking'

Hilaria and Alec Baldwin's son Rafael Thomas is on the mend after breaking his arm "really badly" while playing at the park.

The soon-to-be mom of seven shared on Instagram Thursday that she and Alec were at the hospital "until pretty late" last night while in the emergency room with their 6-year-old son, who now requires an arm cast for "quite a while."

"This is a part of being a parent that is so heartbreaking," Hilaria wrote alongside photos of Rafael at the hospital. "We were with the babies when it happened and to get that call makes your heart sink. His little voice on the phone "I want my mommy"…knowing even the 20 min to get to him is 20 min too long. To not be able to immediately take away their pain and fear…oooof nothing prepares us for this, right?"

"We were at the hospital until pretty late and then we made a bed on our floor (wild sleeper, was afraid he might fall off our bed). How many times he called out for me last night, I do not know," she continued. "At one point I heard him whispering to himself, recounting what happened, saying over and over: 'I broke my arm.' We are relieved that, while it will be a long recovery road, he is certainly on it 💕"

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Hilaria also thanked the staff at Lenox Hill emergency room for "taking such good care of our baby."

"So grateful to the doctors and the nurses for your expertise and kindness," she added.

Along with Rafael, Alec and Hilaria share daughters María Lucía Victoria, 13 months, and Carmen, and sons Leonardo Ángel Charles, 5, Romeo Alejandro David, 3½, and Eduardo "Edu" Pao Lucas, 18 months.

In March, Hilaria announced their family is growing by one more.

"We have 'somos un buen equipo' engraved on our wedding bands. We say that to each other all the time at home — that we're a good team," they told PEOPLE in an exclusive statement. "One of the most beautiful things my children have experienced with a big family is how the heart can grow with every new sibling."

Earlier this month, Hilaria opened up on Instagram about her nerves for this pregnancy. "So much of motherhood is waiting and realizing that there is so much beyond our control. As I approach the time when I lost the second baby in 2019, at 16 weeks, I get more nervous," she wrote in the post's caption. "I get asked all the time how to stay calm and make it through after loss. To be honest, it's hard to stay calm, even if someone hasn't experienced loss."

She went on to say that while she and Alec know the sex of the baby, they are waiting to share that with the world. She said in an Instagram Story that she wants to wait until she's past the point when she had a pregnancy loss in 2019 – at 4 months – before announcing this baby's sex.

Hilaria also shared her desire to be "thoughtful and inclusive" in regards to sharing the sex of the baby given her connection to the LGBTQIA+ community.