Calculating IVF due date


#1

This seems like it would be an obvious answer, but do your RE’s calculate from the date ER or the ET date? All the info on the web looks like ER is the date to use (+2 weeks).

But my doctor said they calculate from the date of transfer, even with a fresh cycle. Which I thought was weird. I know it shouldn’t make all that much difference, but 5 days seems like forever when you’re tiptoeing through the first trimester.

How do your RE’s do it?


#2

My RE is from the date of ER.


#3

I had a frozen transfer of 5 day embryo’s, so I use my transfer date. I like this website because you can use the “calculator” link to try all different options!

IVF.ca - IVF Due Date and Fetal Development Calculator


#4

Thanks Angelique. Yes, I have seen and used that calculator, using the ER date, which is why I thought I was five days further along. The confusion came with my first ultrasound which I thought was 6weeks 3days. And I was measured at 5 weeks 5days. 5 days behind.

I was concerned and my doctor said why? You’re right on track, we measure from date of transfer.

Confusing!


#5

It is +2 weeks from the ER or 12 days from ET

Regards,
Dr. Goral


#6

[quote=dharmadog]This seems like it would be an obvious answer, but do your RE’s calculate from the date ER or the ET date? All the info on the web looks like ER is the date to use (+2 weeks).

But my doctor said they calculate from the date of transfer, even with a fresh cycle. Which I thought was weird. I know it shouldn’t make all that much difference, but 5 days seems like forever when you’re tiptoeing through the first trimester.

How do your RE’s do it?[/quote]

My RE calculates the due date based on the first day of your last period… just like a normal pregnancy. Because the egg is fertilized ~14 days from the first day of your period… just like when you get pregnant naturally.


#7

I guess that would depend on each person’s IVF protocol. My egg retrieval (day of fertilization) was 30 days from the date of my last period - transfer was 35 days later. (I started suppression on the 1st day of my period, stims, 18 days later.) So calculating it from day of LMP wouldn’t make sense.

I still don’t understand why my doctor is dating it from the date of transfer + 2 weeks. But oh well. I guess only the baby knows how old s/he is!


#8

[quote=dharmadog]I guess that would depend on each person’s IVF protocol. My egg retrieval (day of fertilization) was 30 days from the date of my last period - transfer was 35 days later. (I started suppression on the 1st day of my period, stims, 18 days later.) So calculating it from day of LMP wouldn’t make sense.

I still don’t understand why my doctor is dating it from the date of transfer + 2 weeks. But oh well. I guess only the baby knows how old s/he is![/quote]
My ER has always been 14 days after the start of my period for all 3 IVF’s.