Would you want a dating U/S?

[canadiansciencegeek]

Not sure this deserves its own thread.  (Please forgive me if it doesn't.)  I got my BFP this time on my 3rd cycle off BC.  My first two were 41 and 28 days, so I'm not really trusting that calculating EDD off LMP is going to be that accurate.  Would you run with whatever date your doc calculates or would you request a dating U/S?  (I suspect I'm going to have to push for one if that's what I want.)

[beane]

I would, why not? Unless it's a big copay or a huge hassle to get to the appt, I feel like it's good to have an accurate due date, and it's always exciting/fun to see the baby (assuming all is well of course).

[allycat]

I'd say it depends. You said your previous 2 cycles were 41 and 28 days, but what about this one? Going from your LMP, how long was it before you got a positive HPT?

[BookishMomma]

If I were in your shoes, I would definitely want a dating ultrasound.

[canadiansciencegeek]

Jan 20, 2015 13:33:53 GMT -5 allycat said:

I'd say it depends. You said your previous 2 cycles were 41 and 28 days, but what about this one? Going from your LMP, how long was it before you got a positive HPT?

That's a good point.  I had a negative HPT at 28 days and a positive at 32. (Faintly positive on a Wondfo.)  Which to me says >28 day cycle.  But I wasn't temping or charting so it's really a shot in the dark.  

[TrickyJedi]

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

[allycat]

Jan 20, 2015 13:38:05 GMT -5 canadiansciencegeek said:

Jan 20, 2015 13:33:53 GMT -5 allycat said:

I'd say it depends. You said your previous 2 cycles were 41 and 28 days, but what about this one? Going from your LMP, how long was it before you got a positive HPT?

That's a good point.  I had a negative HPT at 28 days and a positive at 32. (Faintly positive on a Wondfo.)  Which to me says >28 day cycle.  But I wasn't temping or charting so it's really a shot in the dark.  

Gotcha. I could be wrong (and someone correct me if I am) but most doctors won't change your EDD, even with a dating ultrasound, unless its more than like 5 days off. (In early ultrasounds, there's a margin of error of +/-3 days.)

So, for me, that difference of 4 days only matters if, at your first ultrasound, things are tracking behind. But in most cases, it wouldn't prove a huge difference. 

[tngrl3]

I have never really had to think about this as a dating ultrasound at your visit is standard at my OB. I would probably ask for one if I were in your place since you have had irregular cycles.

[beane]

Jan 20, 2015 13:39:19 GMT -5 TrickyJedi said:

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

I'm no expert but my understanding is that early/dating U/S are accurate. Having an accurate EDD is important because you would then know later if baby is measuring extremely small for gestational age and therefore there is some problem. Guessing birth weight based on U/S is apparently super inaccurate, but i think it can be useful tell if something is grossly off size-wise.

[ugotstarbucked]

Jan 20, 2015 13:39:19 GMT -5 TrickyJedi said:

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

TJ, a dating ultrasound can help determine if the pregnancy is ectopic, if you have multiples, or if you have an MMC. And of course, determine how big your baby is, to determine a due date if the LMP is not going to be accurate. This is probably the case for you since you have long cycles - your doctor would probably assume you are several weeks further along based on your LMP, but you know when you ovulated and therefore that your LMP isn't going to determine your EDD.

[mandy522]

Jan 20, 2015 13:39:19 GMT -5 TrickyJedi said:

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

Early development is very uniform so doctors can pretty easily date your pregnancy by looking for certain developmental milestones and size. Some OBs have dating ultrasounds as standard practice to determine your due date. Others go off of LMP until the anatomy scan, and then revise if the scan shows development/size differences that would imply a different EDD, or will only provide a dating scan if you have very long and unpredictable cycles so you have no way to know how far along you are. My EDD based on when I ovulated and my LMP are only 2 days apart, so I don't feel really strongly about pushing for a dating u/s (it is not standard practice for my midwives group). If I didn't know when I ovulated, or my EDD based on ovulation was significantly different than based on LMP, I would probably ask for one to establish an accurate due date. I don't know that there are really any cons other than I don't like having a lot of testing done because I find it really stressful. But that's a personal choice.

[TrickyJedi]

Jan 20, 2015 13:46:53 GMT -5 ugotstarbucked said:

Jan 20, 2015 13:39:19 GMT -5 TrickyJedi said:

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

TJ, a dating ultrasound can help determine if the pregnancy is ectopic, if you have multiples, or if you have an MMC. And of course, determine how big your baby is, to determine a due date if the LMP is not going to be accurate. This is probably the case for you since you have long cycles - your doctor would probably assume you are several weeks further along based on your LMP, but you know when you ovulated and therefore that your LMP isn't going to determine your EDD.

Thank you everyone for the education! Just to see the difference I put in the date of my LMP and it gave me an EDD of Sept. 6. Because I temped and used OPKs FF gave me an ovulation date of Jan 5 and EDD of Sept 28, big difference!  It's something I will probably have to discuss with my OB.

Do they normally take your word for it when you are temping and using kits?

[TrickyJedi]

Jan 20, 2015 14:20:56 GMT -5 Fearsy said:

Jan 20, 2015 14:17:12 GMT -5 TrickyJedi said:

Thank you everyone for the education! Just to see the difference I put in the date of my LMP and it gave me an EDD of Sept. 6. Because I temped and used OPKs FF gave me an ovulation date of Jan 5 and EDD of Sept 28, big difference!  It's something I will probably have to discuss with my OB.

Do they normally take your word for it when you are temping and using kits?

Sometimes, but not always. With my first pregnancy, I told them that I was positive of my dates about 4 times before my midwife was like, "I can change your EDD in your chart if you want me to..."

However, mine was only a 6 day difference between LMP and O date. In your case, they will likely want to do a dating ultrasound. Just make sure they know that you know when you O'd!

I'm just going to keep insisting that I know the date and when they ask how..

[London]

Jan 20, 2015 13:46:53 GMT -5 ugotstarbucked said:

Jan 20, 2015 13:39:19 GMT -5 TrickyJedi said:

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

TJ, a dating ultrasound can help determine if the pregnancy is ectopic, if you have multiples, or if you have an MMC. And of course, determine how big your baby is, to determine a due date if the LMP is not going to be accurate. This is probably the case for you since you have long cycles - your doctor would probably assume you are several weeks further along based on your LMP, but you know when you ovulated and therefore that your LMP isn't going to determine your EDD.

I am most interested in a dating ultrasound for the bolded reasons that ugotstarbucked mentioned.

[denvermom]

It's standard practice at my OB and I can't wait to see on Monday. I would want one no matter what though because of the reasons mentioned above.

[allycat]

I guess maybe I should add that my OB does an ultrasound at the first appointment as standard practice, at least as far as my experience goes. So maybe I was the wrong person to answer this?

If my first option for an ultrasound wasn't until the NT scan or the A/S ultrasound, yes, I would probably want a dating ultrasound. I wouldn't want to go in for an NT or A/S and not be able to get the information needed because I was actually a few weeks shy of their requirements.

I'll be over here, being quiet now.

[mandy522]

Jan 20, 2015 14:25:49 GMT -5 London said:

Jan 20, 2015 13:46:53 GMT -5 ugotstarbucked said:

TJ, a dating ultrasound can help determine if the pregnancy is ectopic, if you have multiples, or if you have an MMC. And of course, determine how big your baby is, to determine a due date if the LMP is not going to be accurate. This is probably the case for you since you have long cycles - your doctor would probably assume you are several weeks further along based on your LMP, but you know when you ovulated and therefore that your LMP isn't going to determine your EDD.

I am most interested in a dating ultrasound for the bolded reasons that ugotstarbucked mentioned.

Based on the answers here, I think different practices also use different language to discuss early u/s. My midwives do what they refer to as a viability scan at the first appointment to look for the issues ugotstarbucked mentioned, but they don't date the pregnancy with it. For me, a dating ultrasound is a particular appointment that requires a prescription and a visit to an u/s lab where they'd take more specific measurements to determine gestational age. I'm with allycat, I wouldn't want to skip an early ultrasound completely.

[indseylay]

For my second pregnancy the dating ultrasound proved me right with my dates. This time around according to lmp edd would be 9/7, and according to my own CF and temping it is 9/19 a two week difference. Since this time I'll be needing a csection around 37 weeks, those two weeks make a huge difference.

[indseylay]

^ so yes, I will always want a dating u/s.

[freddy]

A dating US is standard for my OB. My last pregnancy was off LMP by 2.5 week which was a bit surprising, I had only just begun charting and temping so I don't have enough data or experience to accurately determine when I ovulated. I'm glad to have one.

[canadiansciencegeek]

Thanks everyone. At my previous OB, early ultrasounds were done in situations like this, but not routinely. I didn't have my first until the NT scan. I'm now in Canada where early ultrasounds are only done if absolutely necessary. I think I'll try to push for one though!

[andtheheartbreakers]

I'm in Canada too and I have an appointment for a dating ultrasound, and I didn't ask for one. My doctor wants to ensure that there is in fact a baby with a heartbeat in there - she said it's standard practice.

[euphony]

Jan 20, 2015 13:39:19 GMT -5 TrickyJedi said:

This is kinda embarrassing but this is something I don't really know about, would anyone care to inform me of the benefits of this or the cons?

No real con, but being Canadian it is not standard practice. In Canada the first ultrasound is at 12 weeks unless there is a reason to do one earlier. If I had a legit reason to ask for an early ultrasound, I totally would because it would give me peace of mind to see a tiny heart beat. I am not eligible for one, so I will just assume everything is going well until I have reason to believe otherwise. It is up to you, OP. 

[euphony]

Jan 20, 2015 15:50:36 GMT -5 andtheheartbreakers said:

I'm in Canada too and I have an appointment for a dating ultrasound, and I didn't ask for one. My doctor wants to ensure that there is in fact a baby with a heartbeat in there - she said it's standard practice.

It's not. You can look it up. Standard practice in Canada is 12 weeks. You are lucky.

[riderchik]

I'm a Canadian too and I have a dating u/s but I had to ask for it. It is not standard practice. I asked for it because I have big babies and by the time we get past that 10 week mark they are already starting to measure ahead. By the time I have my AS they are usually 10 days bigger. So instead of allowing them to change my dates at 20w I have a dating u/s that they will always stay with that date. This leads to less chance of an unnecessary c/s.

[kbeazly]

I'm also Canadian and I think it's pretty standard practice (w/ my midwives anyways) to do them. I had a dating u/s with DD and have one scheduled for this pregnancy as well. I think if you ask for one and say you are uncertain of the dates it is likely your ob or m/w will oblige.

[andtheheartbreakers]

Jan 20, 2015 16:04:24 GMT -5 euphony said:

Jan 20, 2015 15:50:36 GMT -5 andtheheartbreakers said:

I'm in Canada too and I have an appointment for a dating ultrasound, and I didn't ask for one. My doctor wants to ensure that there is in fact a baby with a heartbeat in there - she said it's standard practice.

It's not. You can look it up. Standard practice in Canada is 12 weeks. You are lucky.

I was just saying what my doctor told me, because I was worried when she said she wanted me to go for an ultrasound between 6 and 8 weeks. I guess it's just standard practice at my doctor's office.

[uclameghan]

I would, yes..

However, I already have one booked for 8 weeks as it's standard procedure in my doctor's office. Also, I O'd on CD 14 and temped to confirm so I guess it's pretty redundant....

[mufflerlove]

I am Canadian and when I mentioned I wasn't sure when my last period started I got scheduled for a dating ultrasound. It can't hurt to ask if you are unsure of your dates. But yeah it doesn't seem to be a standard practice here at all.