Trying, my second MMC was exactly like yours. Smaller baby from the start and then slow growth. The yolk sac was enlarged and the growth was slow and they said to me that was a classic sign of chromosome issues. So it could be that not all the babies are chromosomally normal (we only had 3rd one tested but all the drs said it was also cause for second one).
I think there is definitely no harm in having sperm DNA fragmentation tested because 30% of men have it apparently!
You could also have different causes for each miscarriage??? Some could be bad lack, some could be because of immune issues and some could be because of sperm??? Anyway, nobody ever gave me definitive answers. They just said bad luck/ sperm/ NK cells/ we don't know.
I hope you find an answer or answers soon!
https://www.simply-fertility.com/ne...rent-miscarriage-and-unexplained-infertility/
Sperm DNA fragmentation linked to miscarriages - link above.