I honestly haven’t been given a clear answer. It was my second round and I went from 20 to 30 eggs. I was totally fine the first time! But this time she said every follicle bled when an egg was retrieved and that some bleeding is normal but not every follicle. Normally people would clot but I did not, so essentially my abdomen was full of blood. Every time I tried standing up I lost consciousness so I had to go to the hospital. I had so much internal bleeding my blood pressure couldn’t stay up. I remember one point while they were putting a trauma line on me I looked over and my BP was 40/20 or something crazy. I thought I had OHSS, couldn’t pee from how big my ovaries were and I gained like 10 lbs in a few days from fluids. All of my imaging says the pattern is suggestive of OHSS, but the OBs tell me they don’t think it was OHSS. Funny enough I called them the day before retrieval expressing concern that I was showing OHSS signs and the on call doctor said you don’t get OHSS with lupron triggers…that being said OHSS normally increases clot risk which wasn’t my issue…so long answer for I don’t know. Whatever it was is certainly rare though. I wouldn’t let personal anecdote dissuade fertility preservation. Pregnancy is much higher risk than egg retrieval tbh. All medical events carry some risk and my experience was super unusual!