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Dr. C.
Dr. C., Board Certified
Category: Medical
Satisfied Customers: 3064
Experience:  Physician with 30 years experience
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I had a scan 2 days ago at 8w5d after ivf. The scan showed

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Hi I had a scan 2 days ago at 8w5d after ivf. The scan showed the fetus at the correct size with a heart rate of 169bpm however the sac measures 7w2d with a difference between crl and sac of around 4mm. He didn't seem concerned but after doing research I found that I have over 85% chance of miscarriage? Is this true? Why would a follow up scan or progesterone test not be called for?
Thank you


Do you know what your HCG level is now?

Hi, This is Dr. C. Board-certified Ob-gyne with 30 years of experience. I can help you with this question. In these types of situations the stakes are high to make a "right call" and know when to continue to monitor with hope and when there are sure signs of a non-viable pregnancy. There are very specific guidelines that we follow. Let me get a copy of the guidelines for you. The last time I got them for a customer, I had to cut and paste because the guidelines are on a sbuscription basis only and there are no public links. We can review the guidelines together and see how they apply to your situation. First off, before even looking at the guidelines, I can say that follow-up ultrasound would be the most typical course of action, with a repeat in 1-2 weeks. Did you doctor not schedule one? Progesterone level can also be helpful but not all doctors use that as a guide. I don't. I prefer the combination of beta-HCG levels before the 7th gestationa week (5 weeks after conception) and ultrasound after the 7th week. I'll be right back with the guidelines.
Customer: replied 2 years ago.
I only had my hcg reading to confirm pregnancy. It was around 85 at what would of been 13 days past ovalation. I also had progesterone test which was bordering on low so as well as as suppositories I also inject.
It seems the gestation sac grow 9mm in 13 days from my last scan which was ordered as the fetus was then measuring 4 days behind and had a low heart rate of 118bpm
I'm going to try to attach the guidelines for you. The important thing to look at is Table 1. This may not work but I'll try.
This looks like it may have worked. Let me know if it didn't. The important part is Table 1. A doctor should NEVER say a pregnancy is not viable without meeting the criteria on the table left column. The right column are signs of possible trouble but still high enough chance of a healthy viable pregnancy that we would not be able to say there will be a loss with certainty.
Customer: replied 2 years ago.
So yes there is a high chance of miscarriage? Why would he of just mentioned only as "we don't use the dates from gs once we can measure the crl." He never indicated there was an issue? Would it be because my measurements give quite a bit of room above the fetus as it measured 25.5mm x 32.5mmx 20.5mm??
In your situation, the difference between the sac size and the CRL is 4 mm. So yes, this falls into the category of "suggestive, but not diagnostic of early pregnancy loss". He may not have mentioned it because there is still alot of hope that everything will be ok. We NEVER call a pregnancy non-viable based on a single ultrasound in this type of situation. There is a wide range of error possible with regards ***** ***** measurements. That is because the "caliper" used to measure has a width of about 1 mm and this makes for a built in error that's too high when the sac and CRL are this small.
Dr. C., Board Certified
Category: Medical
Satisfied Customers: 3064
Experience: Physician with 30 years experience
Dr. C. and other Medical Specialists are ready to help you
This is a situation that calls for a follow-up ultrasound in 1 week. The growth at this stage of pregnancy is very rapid and 1 week is enough in most situation to know with certainty whether things are progressing well or not. There is still ALOT of hope. With IVF things are ALWAYs emotionally loaded. It's a terrible roller-coaster of hope, anxiety and grief and hope again, etc. Right now it's too soon to tell how things will go so it's one day at a time but continue to have hope right now. It's too soon to tell. But a repeat ultrasound in 1 week should solve it. Please reply if I can clarify anything or explain anything better. I want to be sure you have the most helpful information for your situation.
Customer: replied 2 years ago.
One more thing then, sorry I'm grasping at straws. If I had an ultrasound 13 days ago and it grew 9mm in that time would that be a good indication things may go my way or should I order another ultrasound?
If the last ultrasound showed a 4mm discrepancy, I would order one more. Also it would bring you some peace of mind. IVF is really loaded as I said and if I had a patient who was still concerned, I would order one more just for the sake of some additional peace of mind. It's possible that your doc felt comfortable enough based on his own experience. Guidelines are developed after the research has already been done and doesn't take into account each IVF centers current experience. It's possible that in 5 years, we'll have new guidelines based on the very experience of your doctor. Anything else?
Customer: replied 2 years ago.
There was an 11mm difference due to the crl measurement at that time being small.
The difference between the crl and gs sac on measurement 1 is currently 11mm. It's the value that has a difference of 4mm." Is the value the mean measurement?
Oh, I misunderstood. In that case you're fine. I was under the impression that the difference between the mean gestational sac diameter and the CRL was 4 mm. Great! That means things are going well. That's why your doc was comfortable. No wonder he didn't order another sac. Good luck with this. I hope it all goes well from here out. I'm sure glad we clarified that.
Customer: replied 2 years ago.
Oh I'm not sure we have?? The value is the mean, right? That difference is 4.6mm.
At scan 1 the difference was 9.8
What I was trying to say though under the 1st measurement where the mean was taken from it had a difference of 11mm which means there quite a bit of space above the baby, no?
Sorry to be a pain!
No pain at all. These things can be tricky and it's important to be accurate. Yes it's the difference of the MEAN gestational sac measurement minus the MEAN CRL. Are you saying that value is 4.6mm at the last u/s? That's so very close to 5mm the cut-off for concern. 11mm is quite a bit of space between the baby (CRL) and the gestational sac wall. Please reply if we haven't straightened this out yet. It's important to be clear.
Customer: replied 2 years ago.
Yes 4.6mm is the mean at the most recent scan. Measurement 1 seems correct for the gestational age at 32.5mm but the other readings of 20.5 and 23.6 are bringing the mean value right down.
Oh now I understand what you meant earlier. Yes, some measurements of the CRL and Sac are more accurate than others. It depends on the angle we're looking at, fullness of the bladder etc. So it's completely possible that the 32.5 is closer to the actual real mean. Does it seem like I'm understanding correctly what you were trying to explain now?
Customer: replied 2 years ago.
I'm not sure?
The Dr took those three measurements to work out the mean. 32.5 x 2.05 x 2.36. I thought they were the length, width and breadth? Are they three measurements of one length? If so that's a huge difference in measurements?
Well now you listed the decimal points differently. Where are the actual decimal points on the 2nd 2 measurements?
It might help if you got a copy of the actual ultrasound report.
Customer: replied 2 years ago.
How do I attach it?
There should be a paperclip icon on your screen. You'll need a scanner to scan it into your computer, then attach using the icon.
Usually the sac is measured in 3 dimensions while the CRL only in one dimension.
We'd take the mean of the 3 sac dimensions and subtract the CRL from it. If more than 1 CRL was taken and were good, we'd average them.
Customer: replied 2 years ago.
No paper clip showing but only one measurement was taken for crl which was 8.6
Customer: replied 2 years ago.
Sorry he did them in cm. forgot to convert to mm. 2nd 20.5 3rd 23.6mm
8.6 doesn't seem right for a CRL.
How many weeks again? 8.6 mm, so you're very early.
Customer: replied 2 years ago.
Sorry that was bpd! 20.9mm
That's better.
Yes, you're right, the difference is 4.63, just under the 5mm reassuring number. . So yes the mean sac may be dragged down because the sac shape is a little "squished". My advice stays the same as earlier. I'd do a repeat u/s in 1-2 weeks for reassurance. But your docs experience may be giving him information otherwise because he does a lot of IVF and knows more about how these measurements tend to run on their protocols.
Anything else for today?
Customer: replied 2 years ago.
Thank you for your patience!
You're welcome. I'm glad to help. Good luck and I hope all goes well from here out.You can ask for me in the future if you have additional questions by using the box on my profile page. ***** helps if you put "Dr. C. only please" in the tag line. I'll get an email notifying that I have a customer waiting so I can log-in if not already on-line. Again good luck!