How do the “chances of miscarriage by week” charts count weeks??

Question

Based off of the first day of my last period I’m 12 weeks today (SO grateful as this is following multiple early miscarriages) but the baby is measuring 10w 4d with a strong heartbeat. I was just wondering if anyone knew how all of those “miscarriage risk by week” charts counted weeks, by period date or actual size of the baby?

Answer

The by week isnt, in my opinion, accurate. You have a reduced rate of a "conventional" miscarriage if you hear a heartbeat before 8 weeks but still have a risk of missed miscarriage. Based on a lot of posts I have seen the likelihood of a missed miscarriage or other miscarriage if you hear a heartbeat after 10 weeks is REALLY LOW. Most folks with a missed miscarriage have the growth stopping before 9 weeks. I have seen SOME posts of a miscarriage after 10 weeks confirmation but it is SUPER RARE. I think you are safe!! This one stuck and pounding its little heart for you! From hear on out you will likely still be checking for blood neurotically and anxiously feel every twinge and every so often hit a moment of "wait, this is happening". CONGRATS, remember to keep breathing deep to relax. ❤❤❤

Answer

I'm 10w4d today and our official ultrasound is on Tuesday. We saw and heard our little jelly beans heartbeat at 8w6d. What a heavenly sight and sound it was!

Answer

Pretty sure they go by weeks since your period. Everything else does.