Maybe I can help a little with this. We had this exact situation in March when I was 34 weeks pregnant with our little girl. Overnight she died and I ended up delivering by c section as she was transverse. There are no words for me to describe the total shock and devastation that followed her loss. The crazy leaky boobs and no baby to feed, the c section scar breaking down and becoming infected, the awful awful sleepless nights of dreams and hearing phantom babies crying, the darkest days I have ever known in my life.
All around me the girls who were pregnant at the same time as me continued with their healthy pregnancies and I was of course delighted for them, but suddenly no one could make eye contact with me. Moms with new babies scuttled away or crossed the street from me. It felt as though they were scared they would "catch" this horrific affliction from me.
The people who were totally normal were such a breath of fresh air. It's not as though they were reminding me of my beautiful dead daughter, trust me I had not forgotten! They recognized that in no way did we want THEIR child. We wanted OUR child. They were straight up about things and recognized that the people who didn't keep us in the loop with their kids or pregnancies actually hurt us more. My wonderful best friend did more for us than I can ever explain. She was there to listen, to talk. She talks about my baby by name and isn't scared to mention her.
If this whole awful time can given me one new skill it is to help other people who have experienced stillbirth and those who support them. Your brother will be delighted for you. No one who is in this club wants to be a member and none of us wish for any new members. We just survive.
Sorry this is long, but it's something I have lived and I know that silence and trying to protect those of us who have experienced stillbirth actually makes it harder. I hope this is helpful to even just one person in the world. When you have the conversation with your brother talk about their baby by name and don't be scared to mention the stillbirth. Good luck!!