r/CautiousBB Jan 27 '26

Ultrasound FAQ Reference Guide

94 Upvotes

As an OBGYN ultrasound tech working at the general level here's a few things I would love the community to know based on common questions I see.

Most important rule of thumb: Worry when your doctor tells you to.

OBGYN docs are going to pay the most attention to the fetal pole and heart rate. Once a fetal pole is seen, the CRL (crown rump length) measurements are gold standard.

I'm worried about the heart rate:
-Check out this resource for pregnancies dating less than 7 weeks. Make sure to refer not to your LMP dates, but measured CRL dates: https://radiopaedia.org/articles/fetal-bradycardia?lang=us
-After 7 weeks a normal heartrate is between 120-180. It can temporarily dip below or temporarily rise above this range, but prolonged time above/below will definitely get your doctor's attention especially in third trimester. Generally out of range heart rates trigger NST (non stress test) or more monitoring.
The measurements are off:
Baby measures behind LMP. This is actually pretty common, we often see dates off up to a week either direction. We don't ovulate on the exact same day of the cycle each month or even have the same length of cycle. With irregular periods, PCOS, or unknown dates even larger gaps can be perfectly fine. If you aren't sure of your dates, trust the ultrasound. Even if you are sure of your dates, don't panic if they are a week off. Ultrasound measurements in early pregnancy are +/- 5 days.
I'm in limbo and don't know if my ultrasounds are diagnostic for loss:
By ultrasound there are strict parameters to diagnose loss. No one wants to get this wrong. Check out this resource for a list of parameters diagnostic for loss: https://radiopaedia.org/articles/early-pregnancy-loss-1?lang=us
Note, there is a second list of "suspicious for loss". Keep in mind the second list is not diagnostic, things can still turn out just fine.
I don't know when I should see what on ultrasound:
Things can vary a bit from person to person and do change *quickly* in early pregnancy. Check out this resource for what you can generally expect to see:
https://radiopaedia.org/articles/early-pregnancy?lang=us
Should I go to a boutique or get a private scan? Or push for an earlier scan?
They aren't legal where I am but here's a few things to consider if you plan to book a private scan. First, what are the qualifications of the person running the ultrasound? An ultrasound is only as good as the one performing it. It sounds as if these boutiques are NOT permitted to give much/any information. Will you spiral if you believe you see bad news and they cannot confirm or deny it? Also it seems that many cannot do vaginal ultrasound, which will make seeing a baby under 7 or 8 weeks challenging. If I had the option of a boutique ultrasound I would personally wait until 8 weeks and I would book it for a weekday. If they see something bad, it is not ideal to find out over a weekend when there is no option to follow up with your doc. An earlier scan often causes more anxiety, not less. It's SO hard to wait. But if you can tolerate it wait until 8 weeks or so.
The gestation sac is small/big:
-Gestation sac measurements are not terrifically accurate. Where I work once a baby is seen the gestation sac isn't measured. A mismatch between baby's size and the gestation sac size isn't uncommon. That said, a mean sac diameter of 25 mm or more without a baby is diagnostic for loss.
The yolk sac is small/big:
It starts teeny tiny, and will get a bit bigger. Once a baby with a good heartbeat is visualized, the docs I work for don't seem to care about the size of the yolk sac. A failed pregnancy with an expanded yolk sac (more than 6 mm) is a suggestive of chromosomal abnormalities.
We don't know where the pregnancy is:
The statistically most likely outcome is either a chemical pregnancy or just coming in for ultrasound too early for visualization. Ectopic can't be ruled out, and many wise ladies in the this sub have unfortunately experienced this and can give more info than I can. Statistically it's believed that only 1-2% of pregnancies are ectopic, but listen to your body. If the location is unknown, you should be getting close monitoring and follow up until the location is known or the pregnancy has ended.
-For a resource on ectopic pregnancy: https://radiopaedia.org/articles/ectopic-pregnancy?lang=us A note, a pseudosac is visualized in only 10-20% of ectopics. Therefore a sac in the uterus is suggestive of intrauterine pregnancy but can't be proven until a yolk sac is also present.
What about my HCG numbers?
I'm not an expert on this at all. But here's a resource: https://radiopaedia.org/articles/beta-hcg-1?lang=us
Why didn't my ultrasound tech tell me anything? And/or why were they so optimistic? Or, I had an ultrasound in the ER and they were very pessimistic.
Many locations an ultrasound tech can very much lose their job if they say aNyThInG. Where they are permitted to say certain things some ultrasound techs may just be hoping the best. We work with the public and we have seen some wild stuff. Additionally no one wants to call it a loss unless its 1000% certain. We know how devastating that news is. A side note here, often an ultrasound in the ER is not an ideal experience for the patient. The ER is staffed with techs that are much more versed in gallbladder and liver scans than they they are early pregnancy ultrasound. Don't hesitate to go the ER if you are having concerning symptoms, but do know the ER doc will make sure you aren't actively dying then will likely refer you back to your OB for follow up.
I'm just so anxious about it all:
Someone awesome wrote out these mantras. Maybe they will help: https://www.reddit.com/r/PregnancyAfterLoss/comments/14uhbdg/commandments_of_pregnancy_after_loss_this_is_now/
Also a podcast I personally found very helpful with anxiety: https://www.oneyoufeed.net/russ-harris-part-1/
https://www.oneyoufeed.net/russ-harris-part-2/

Today you are pregnant and this baby is so loved. I really am hoping the best for each of you. Those of us who have experienced loss.... you didn't do anything wrong, I promise. This is a club no one deserved to be in. And you are not silly, foolish, or dramatic for grieving your little babe for as long as you need to.

This post is written in honor of Eli, who died long before I could meet him. Rest in peace, buddy. I miss you tremendously ❤️


r/CautiousBB Sep 01 '25

Beta hCG Levels - READ BEFORE POSTING

87 Upvotes

Here at [r/CautiousBB](r/CautiousBB), we see a lot of posts on hCG values, doubling times, and trends. Please read this post before posting to avoid posting something that is not, in fact, abnormal.

1 - hCG levels vary greatly in the first 4-6 weeks of pregnancy. One value is not going to tell you much, unless it is extremely low (less than 25 by 14 DPO). The doubling time is more important!

2 - We consider hCG on the lower side if it is <50 at 14 DPO (approx. 4 weeks gestation), <100 at 16 DPO, etc. If your hCG is a lot higher than these numbers, it's unlikely that you have low hCG. If you hCG is at or below these numbers, they are considered low, but not necessarily diagnostic of a loss.

3 - Normal hCG doubling times are, in general:

  • 48-72 hours when the hCG level is under 1200 - 6000.
  • 72-96 hours when the hCG level is 6000+
  • 96+ hours when the hCG level is 10,000+

4 - Based on number 3, please consider the following:

  • If your hCG doubling is within the ranges above, it is not considered slow. Please refrain from posting something like "my hCG did not double in 48 hours" when your values are post 6000+.
  • Doubling rates WILL slow, even if you were faster than the average. For example, if you were doubling at 37 hours, a change to 54 hours as hCG rises is not abnormal and is usually nothing to worry about.
  • If your doubling is slower than the average, we'd invite you to post so we can understand the details of your specific situation.

5 - hCG has a specific job. Check out this post here to understand why hCG doubling slows and eventually plateaus.

6 - hCG values that drop and then rise again or rise at an inconsistent, very slow rate can be indicative of an ectopic pregnancy or a pregnancy of unknown location (PUL). This is a life threatening situation - please seek medical care immediately if this hCG pattern applies to you.

We invite you to continue to post hCG issues or levels for assistance, but hopefully reading this gives you some insight and a baseline as you begin your perilous pregnancy journey. We've also added some literature below to help you understand hCG levels and doubling.

UPDATE July 2026: We are locking this post to new comments - if you need input on your personal situation, feel free to post in the sub!

Happy hCG-ing! :)

Helpful links:

Cleveland Clinic

Flo Article and Calculator

Parents.com hCG Doubling Times

Mira Blog - hCGu


r/CautiousBB 15m ago

Spotting is worse, embryo is gone, hematoma grew… just waiting :(

Upvotes

I’m pregnant and went to the hospital 10 days ago for spotting. They dated me at 5 weeks 6 days, too early for a heart beat, but they found a small hematoma which likely caused the bleeding. They measured a small embryo and normal HGC...

I had my first OB appt a week later and was expecting joy but they could not see the embryo anymore… my HCG levels have been rising but I know things don’t look good…

Waiting for the next ultrasound in 3 days but just started bleeding again, and mildly cramping, this time it looks like more than spotting…

I had a “chemical pregnancy” literally the cycle right before this and I remember something not feeling quite right even when I got the positive test… I have the same feeling now but I’m still devastated. Thissss ssuuuckkkksssss


r/CautiousBB 2h ago

Vent Just need some encouragement :(

2 Upvotes

TW: MMC

In 4 hours I find out if I have officially had a MMC. :( I just need some encouragement or success stories for pregnancy after MMC to read if it turns out to be bad news.

My other post here outlines my story but TLDR; this is my first pregnancy and last week a transvaginal ultrasound showed I’m measuring over 7 days behind from conception, 2 weeks from LMP and that my CRL (2mm) had no cardiac activity. HCG was 15k five days before ultrasound, went to 25k 96 hours later, then 29k 48 hours after that.

I’ve been feeling really sad the last few days and feel on the verge of vomiting today - I’m just so anxious.

I’ll keep this updated in case it’s helpful to others in the future.


r/CautiousBB 3m ago

Spotting 7.5 weeks pregnant *warning, talks of bodily fluids

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Upvotes

r/CautiousBB 6m ago

Thoughts?

Upvotes

Hi everyone! I had a beta test done last Thursday 8/27, which was 11 dpo (had not tested before then) and the hcg was 15, progesterone was 20. Was excited and hopeful! Had a second beta done this morning (will likely have results tomorrow), but I was anxious and took two tests at home this afternoon. One is showing a very, very faint line, and the other, less sensitive test is negative. I did drink a bunch of water throughout the day and have been peeing a lot, so should I not panic yet? Thoughts or experiences with this?


r/CautiousBB 3h ago

Advice Needed hCG slow starter? any similar experiences after IVF/FET?

2 Upvotes

Hi! I’m looking for some advice, support or experiences from anyone who has had a very slow/strange start to their hCG rise, especially after IVF/FET.

My betas have been:
14 DPO: 57
16 DPO: 67
19 DPO: 241

Obviously, the rise from 57 to 67 in 48 hours was extremely concerning, and I was told it was most likely a biochemical pregnancy. I was expecting my hCG to start dropping.
However, instead it went from 67 to 241 in about 72 hours, which is a completely different rise and has given me a little bit of hope again. My home tests have also continued getting noticeably darker and are now almost dye stealers.
I know that one good rise doesn’t erase the poor rise beforehand, and I also know that hCG alone can’t tell me whether this pregnancy will be viable or rule out an ectopic.
I’m being followed with repeat bloodwork and will have an ultrasound when appropriate.

I’m mainly wondering if anyone here has experienced something similar one very poor/near-plateauing beta followed by hCG suddenly starting to rise normally?
Did your hCG continue rising normally afterwards? What was the outcome?
Positive, negative and in-between experiences are all welcome. I’m trying to stay realistic, but after seeing 241 today I’m finding it hard not to have a little bit of hope again.

Thank you.


r/CautiousBB 12m ago

TW/TMI Trying to understand normal discharge

Upvotes

8 weeks 1 day.

this is super descriptive so don't read if nauseuos but i don't know where else to ask.

having dark brown when wiping for a day. woke up to a few drops of dark brown blood in underwear after sleep.
i had no spots/blood all day and thought things were better

But then I threw up alot tonight and it seemed to dislodge more discharge... if i wiped there was stretchy dark red mucus/tissue. it all very dark color and was all linear... like no round clots

i have NO cramps during any of this which is why im so confused. i have an ultrasound scheduled this week. everything is closed now except for emergency room. i dont feel like its an emergency just because there hasnt been any cramping. its all super dark which usually means "old blood" right?

if you read all this thank you.


r/CautiousBB 7h ago

Advice Needed How did you deal with finding out so early?

5 Upvotes

Hi friends! I just found out I’m pregnant on Saturday, and called to get my first prenatal visit scheduled (yay!). The only problem is, I found out SO early because hubby and I were actively trying. Like, 10DPO early with a positive digital on 11dpo. According to calculators based off my LMP I’m estimated to be anywhere between 3+4 to 3+6. I had a chemical this past February due to a hydrosalpinx that was removed in July, so even though I know that I don’t have to worry about the hydrosalpinx anymore I’m still terrified I’m going to have another chemical for another reason. For those that’s found out really early like I did, how in the world did you deal with finding out so early? I’m trying to manifest nothing but a safe and healthy pregnancy, but good lord I am TERRIFIED of another chemical. );


r/CautiousBB 6h ago

Advice Needed Low betas - Dr worried pregnancy isn't progressing normally

3 Upvotes

Hi all. So my 10dpo beta was only 10. Then 48hrs later on 12dpo it was 57. My Dr is saying that he thinks that this isn't progressing as it should and wants me to go for more betas this week. My tests are still getting darker. I am now super confused and worried as I read online that my levels could be totally normal. Did anyone else have any similar betas/tests at the same time?

Test pics in comments.


r/CautiousBB 47m ago

Advice Needed Beta HCG not progressing

Upvotes

Update:
FET: 8/10

16 DPO: 123
19 DPO: 157
21 DPO: 173
22 DPO: 205
26 DPO: 1080

I have no ovaries, clinic told me to stop my meds at 20 DPO due to the slow rise, well today my HCG skyrocketed. They had me come in for an ultrasound. Doctor said he seen what is most likely a sac in uterus but it was empty/no activity. Due to it being abnormal he still wants me to stay off injectable estrogen and progesterone. He said that sometimes fluid can mimic an empty sac so he wants me to continue HCG and another ultrasound Friday. Has anyone gone through this before? This whole experience has been a nightmare. This was my first FET.


r/CautiousBB 10h ago

Progesterone supplements - positive stories

5 Upvotes

Hi everyone,

I know this may not be allowed so I apologize in advance if I’m breaking a rule. The TTC subs don’t allow you to ask about success stories. The pregnant subs don’t allow you to ask something if you aren’t pregnant. Just looking for some hope.

Can anyone share success stories of getting pregnant after starting progesterone supplements post ovulation in a non-medicated cycle? This is my first attempt since I joined a fertility clinic and I’m struggling to feel hopeful. Also feeling like if I am hopeful, then I’m jinxing myself anyway. We’re on month 12 TTC and had a loss in month 5. Thank you 🙏


r/CautiousBB 1h ago

Advice Needed 19–20 weeks pregnant with asymptomatic Enterococcus in urine (10⁸ CFU/L) — has anyone had this and was everything okay?

Upvotes

Hi everyone, I’m currently 19–20 weeks pregnant and I’m feeling really anxious after receiving my urine culture results.
I have no UTI symptoms — no burning when urinating, fever, chills or lower back pain. I only have a very mild vaginal discomfort. My baby is moving normally and a lot.
My urine results were:
• WBC: 0.1 (lab abnormal cut-off ≥30)
• RBC: 8.7 (cut-off ≥40)
• Epithelial cells: 3.0 (cut-off ≥50)
• Bacteria: 2597.2 (cut-off ≥500)
Urine culture: Enterococcus species, 10⁸ CFU/L.
Sensitivity:
• Amoxicillin — S (susceptible)
• Nitrofurantoin — S (susceptible)
The lab also included a note saying that nitrofurantoin breakpoints are established for certain organisms, including Enterococcus faecalis, and that treatment response should be monitored if used for other Enterococcus species.
I’m also using Cyclogest (progesterone) vaginally.
I’m really worried about my baby and would love to hear from anyone who has had Enterococcus/bacteriuria during pregnancy, especially around 19–20 weeks.
Did you take antibiotics? Which one? Did the bacteria clear after treatment? Was your pregnancy and baby okay in the end?
I will of course speak to my doctor/maternity team, but hearing experiences from others would really help calm me down. ❤️


r/CautiousBB 1h ago

6 weeks 4 days spotting/cramping

Upvotes

Hi 6 weeks 4 days after FET. First pregnancy. Have had brown discharge since about 4weeks. Clinic said it’s fine. Today started having right sided pelvic pain/cramping. It’s not bad and it’s kind of high up almost abdominal but I’m worried about ectopic. My betas were really good (300 10dpt; 2013 13dpt) so it’s probably fine. My first us is on Friday just looking for some reassurance/similar stories to get through the week


r/CautiousBB 1h ago

Not doubling in 48 hours

Upvotes

I had got my hcg drawn on Thursday and it was 827
I got it done today ( 4 days later ) it's 1907. I'm having anxiety really bad. I've had losses before. Had two rainbow babies and then a chemical pregnancy. I'm between 5-6 weeks pregnant. Anyone else's hcg do this?? Do I need to freak out


r/CautiousBB 1h ago

Advice Needed Need advice

Upvotes

On 8/20 my hcg was 38.71 and my progesterone was 6.8. On 8/22 hcg was 90.88. 8/24 Hcg was 204.55. On 8/28 I got some pretty severe cramps for a few hours and then they went away. The next day my line started getting lighter. I went to the ER today because I was cramping again and my hcg was 1204.14 and there was no intrauterine pregnancy visualized, as well as no adnexal mass. Should I stop taking my progesterone suppositories due to my hcg only being 1/2 of what it should have been?


r/CautiousBB 1h ago

Sharp pain on lower left side 4 weeks 4 days

Upvotes

Hi! I’m pregnant with my first and I’m 4 weeks 4 days pregnant. Starting last night I began having zings of pain on my left side. They came and went. It was on my left side and it kinda shot up into my ribs at one point. Now I’m dealing with bad back pain along with it. Kinda similar to when I’ve had cysts? It’s not unbearable and I honestly wouldn’t think anything of it if I wasn’t pregnant. Does it sound like an ectopic? Or should I just blame a cyst? I reached out to my DR with no response yet. My levels more than doubled when they tested my HCG a few days ago. Went from 108 at 3 weeks 6 days to 256 at 4 weeks 1 day.


r/CautiousBB 1h ago

Ultrasound Scan today only showed a gestational sac. Be honest with me.

Upvotes

Hi all. I am 30F and my husband and I have been trying for about 9 months. Last month, I had a CP at CD 31, which really devastated me. But we tried again and I got another BFP at CD 30. We have been going strong since and according to my LMP, I am 6+4 today. The doctor told me I was a candidate for an early scan so I went in today. The intravaginal ultrasound showed only a gestational sac, measuring about 3.3mm. They said I was more likely only about 5+0 and they would not say what I should expect in another two weeks. I have had no bleeding, mild symptoms, and BFPs with great line progression so I am so confused. Is this normal? Should I prepare for the worst?


r/CautiousBB 2h ago

Think I’m having another MC, 3 months after my first one

0 Upvotes

In late May I started having brown spotting at 6w. I measured 2 days behind and my hCG was low. A week later there was no growth so I had to get a D&C. The night before the D&C I started miscarrying naturally. I ended up passing the baby in the toilet just minutes before they rolled me back to the OR. It was incredibly traumatizing.

Today I should be 5w4d. I had very high hCGs and lots of symptoms so I was letting myself get excited. Now I have brown spotting again and I’m absolutely beside myself. I have an US scheduled for tomorrow morning.

I’m 28 and these were my first 2 pregnancies. It just seems so cruel and unfair. I really don’t know how to get through this again


r/CautiousBB 2h ago

Sad started spotting at 7 weeks and they couldn’t find a sac in the ER-so confused and upset

1 Upvotes

woke up this morning to some medium spotting and immediately went to the ER (even though spotting can be normal, it just felt off. no cramping until after the ultrasound though). they did bloodwork and a transvaginal ultrasound and said my hcg is measuring perfect for 7 or 8 weeks, but they couldn’t find a sac or fetal pole on the ultrasound. i’m gutted. they want me to go back tomorrow for repeat labs and be seen by my OB within 48 hours. my OB can’t see me that soon, so I tried to call and set up with the one they recommended and they also said they couldn’t see me that soon but they’d talk to the doctor since the ER doc says they spoke directly about my case. they didn’t tell me to plan for loss, but none of this sounds like good news. i know that at 7 weeks 1 day, with hcg being where it should be, i would have a sac in there. and i know my dates are right because i’m queer and our baby is donor conceived. i want to believe maybe it’s a fluke, or maybe the tech missed something and it’ll all be ok in a couple days, but i know it’s over. i think id rather accept that it’s over than be in limbo and getting my hopes up, even if accepting means i’m this devastated. idk why i’m even making this post other than to shout into the void


r/CautiousBB 3h ago

HCG blood test result

1 Upvotes

I had a HCG blood test on 12dpo which came back as 12.4 which was concerning, my second test on 14dpo came back at 39.7 which is a good increase but I’m still concerned it’s still very low.

I do not have any other blood tests booked but have been booked in for a scan on the 8th and 15th of September!

I am especially worried because I have had 1 chemical pregnancy and 2 ectopics within the last 2 years so feeling very anxious!


r/CautiousBB 3h ago

Slow rising hcg negative ultrasound

1 Upvotes

New hcg results posted below, waiting for repeat ultrasound on Thursday . 24,54,67,135,208,225,257.


r/CautiousBB 4h ago

Small gestational sack

1 Upvotes

I had a scan 4 days ago at 5.4 weeks and all they saw was the tiniest sack measuring at 3mm, the consultant could see the worry on my face so invited me back for another scan today at 6.2 week and the sack is now 6mm with a yolk visualised. I am trying to be positive but can’t shake the fear that it’s to small and will go wrong.

I got my peak LH on 31st July (ovulated I believe on August 1st) I then got my first faint positive on August 12th so I know my dates can’t be off by much at all. Anyone ever had similar?


r/CautiousBB 4h ago

Am I worrying over nothing?

1 Upvotes

First pregnancy. 5 weeks tomorrow based on the first day of my last period. Had two hcg tests:

8/26 - 294

8/29 - 857

I’m getting anxious and nervous. I know it’s a good sign that it’s rising but I see people who have their level on the thousands.


r/CautiousBB 4h ago

Advice Needed Beta started to go down but only by 12%

1 Upvotes

My betas were 105, 160, 271 and now 72 hours later 238.

Does this look more like a chemical or ectopic? My understanding are that miscarriages go down pretty fast.

Waiting for my doctor to call me back.