AITAH for telling my brother and SIL not to come to a family gathering?

I (31F) am 8 months pregnant with a high-risk pregnancy. I could go into labor any day now. I have a younger brother (YB, 27) and an older brother (OB, 33). OB is married with a 2-year-old and a 7-month-old.

We rarely see OB’s family for a few reasons:

• They live 45 mins away, OB doesn't drive, and public transit with toddlers is hard.
• His wife has CPTSD from childhood trauma, is deeply suspicious of us and keeps her distance. She is also a doctor and fiercely protective of her kids. We all try our best to respect her boundries.
• OB is an undiagnosed autistic. He’s brilliant but has the emotional maturity of a toddler. He cannot handle any criticism and gets easily offended. We grew up very close and I spent my life acting as his emotional regulator. Now he only calls me when he needs emotional support or cuts contact for weeks.

The Situation:

YB planned his 27th birthday party at our parents' house. We were thrilled because OB's kids have almost never been there. However, the morning of the party, OB called our mom saying his son had a fever. Mom initially told him to stay home to protect me and our older parents.

An hour later, OB called back crying and begging for a ride anyway, claiming it was "just a small fever." Feeling guilty, my mom actually drove all the way to get them before calling to ask my opinion.

I told her it was a terrible idea.

It left me with three options: complicate my high-risk pregnancy even more, skip the party and isolate from my newly-contagious family (dangerous if I go into early labor), or make everyone upset by telling them to stay home.

My mom didn't want to be the bad guy, so I called OB to express my discomfort. His wife intercepted the phone and said that, as a doctor and a mom, she understood—but since I was the one at risk, I should stay home and miss the party. She passive-aggressively asked, "So do you prefer we don't come?" I said yes, and she hung up. OB said nothing.

Immediately after hanging up, my brother had a full-blown meltdown. He called my mom (who was already waiting in her car outside their house), started yelling and accused her of ruining everything. I think deep down he knew that if the roles were reversed, there is no way in hell they would let me near them with a fever.

Mom turned around and came home. We had a lovely party without them, but now OB and his wife are furious at everyone. OB is giving me the silent treatment and only calling our parents to scold them.

AITA?