Measuring and interpreting Blood hCG to Assess Pregnancy Viability Following ART Treatments

I know of no medical announcement associated with the degree of emotional anticipation and anguish as that associated with a pending diagnosis/confirmation of pregnancy following infertility treatment. In fact, hardly a day goes by where I am not confronted by a patient anxiously seeking interpretation of a pregnancy test result.

Testing urine or blood for the presence of human chorionic gonadotropin (hCG) is the most effective and reliable way to confirm conception. The former, is far less expensive than the latter and is the most common method used. It is also more convenient because it can be performed in the convenience of the home setting. However, urine hCG testing for pregnancy is not nearly as reliable or as sensitive e as is blood hCG testing. Blood testing can detect implantation several days earlier than can a urine test. Modern pregnancy urine test kits can detect hCG about 16-18 days following ovulation (or 2-3 days after having missed a menstrual period), while blood tests can detect hCG, 12-13 days post-ovulation (i.e. even prior to menstruation).

The ability to detect hCG in the blood as early as possible and thereupon to track its increase, is particularly valuable in women undergoing controlled ovarian stimulation (COS) with or without intrauterine insemination (IUI) or after IVF. The earlier hCG can be detected in the blood and its concentration measured, the sooner levels can be tracked serially over time and so provide valuable information about the effectiveness of implantation, and the potential viability of the developing conceptus.

There are a few important points that should be considered when it comes to measuring interpreting blood hCG levels. These include the following:

  • All modern day blood (and urine) hCG tests are highly specific in that they measure exclusively for hCG. There is in fact no cross-reactivity with other hormones such as estrogen, progesterone or LH.
  • Post conception hCG levels, measured 10 days post ovulation or egg retrieval can vary widely (ranging from 5mIU/ml to above 400mIU/ml. The level will double every 48–72 hours up to the 6th week of gestation whereupon the doubling rate starts to slow down to about 96 hours. An hCG level of 13,000-290, 0000 mIU/ml is reached by the end of the 1st trimester (12 weeks) whereupon it slowly declines to approximately 26,000– 300,000 mIU/ml by full term. Below are the average hCG levels during the first trimester:
    • 3 weeks LMP: 5 – 50 mIU/ml
    • 4 weeks LMP: 5 – 426 mIU/ml
    • 5 weeks LMP: 18 – 7,340 mIU/ml
    • 6 weeks LMP: 1,080 – 56,500 mIU/ml
    • 7 – 8 weeks LMP: 7, 650 – 229,000 mIU/ml
    • 9 – 12 weeks LMP: 25,700 – 288,000 mIU/ml
    • A single hCG blood level is not sufficient to assess the viability of an implanting embryo. Caution should be used in making too much of an initial hCG level. This is because a normal pregnancy can start with relatively low hCG blood levels. It is the rate of the rise of the blood hCG level that is relevant.
    • In some cases the initially hCG level is within the normal range, but then fails to double in the ensuing 48-72hours. In some cases it might even plateau or decline, only to start doubling appropriately thereafter. When this happens, it could be due to:
      • A recovering implantation, destined to develop into a clinical gestation
      • A failing implantation (a chemical pregnancy)
      • A multiple pregnancy which is spontaneously reducing (i.e., one or more of the concepti is being lost) or,
      • An ectopic pregnancy which will either absorb spontaneously (a chemical-tubal gestation), or evolve into a full blown tubal pregnancy continue and declare itself through characteristic symptoms and signs of an intraperitoneal bleed.
  •  The blood hCG test needs to be repeated at least once after 48h and in some cases it  will need to be repeated one or more times (at 48h intervals) thereafter, to confirm that implantation is progressing normally.
  • Ultimately the diagnosis of a viable pregnancy requires confirmation of the presence of an intrauterine gestational sac by ultrasound examination. The earliest that this can be achieved is when the beta hCG level exceeds 1,000mIU/ml (i.e., around 5-6 weeks).
  • Most physicians prefer to defer the performance of a routine US diagnosis of pregnancy until closer to the 7th week. This is because by that time, cardiac activity should be clearly detectable, allowing for more reliable assessment of pregnancy viability.
  • There are cases where the blood beta hCG level is extraordinarily high or the rate of rise is well above the normal doubling rate. The commonest explanation is that more than one pregnancy has implanted. However in some cases it can point to a molar pregnancy  
  • Finally, there on rare occasions, conditions unrelated to pregnancy can result in detectable hCG levels in blood and urine. They include ovarian tumors that produce hCG, such as certain types of cystic teratomas (dermoid cysts) and some ovarian cancers such as dysgerminomas.

793 Comments

Nicolina

Hi there! So I am 5 days passed my expected period, and my test lines are getting darker but they are not dark yet like I feel they should be at this point (with my other kids the lines were very strong at this point). I got blood work done yesterday and my hcg levels were only 64, but progesterone and estradiol looked fine. Any idea what could be going on? If this is not going to stick (which I’m totally fine with actually) how quickly will I know? This limbo stuff is so hard! Thank you for taking the time to respond to everyone!!

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Dr. Geoffrey Sher

Interpretation of the urine test can be subjective. I would repeat the quantitative hCG test in 2 days and if need be again 2 days later to determine if the levels are rising appropriately.

Geoff Sher

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sarah

my HCG 10dp5dt was 347 , the 14dp5dt 2450, 18dp 7500
progesterone hovering around 90 atm
i hope I am tracking okay?

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Michelle

Thank you for the hope
Today’s results were 267 so climbing about the same. They did an ultra sound and nothing was showing. They have booked me in next Thursday for another ultra sound

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Dr. Geoffrey Sher

I concur with that decision, A repeat hCG level should also be measured in a few days time.

Geoff Sher

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Michelle

I did a 5 day blastocyst transfer on Oct 28th.
My HCG level on Nov 4th was 26.
But on Nov 6th it only went to 30.
Nov 8th – 50.7
Nov 12th 184
Doesn’t look great. The doctor is telling me i will miscarry

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Dr. Geoffrey Sher

I would not write this off quite yet!

Do an US in 10 days time and please keep me in the loop!

Geoff Sher

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Casey G

I had a 5 day transfer with 2 follicles

My first HCG level was 1,725 14dpo
2nd test had my HCG levels at 3715 16dpo

Does this sound like a multiple pregnancy?

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Anxiously Waiting

Date of 1 embryo day 5 FET: 10/28 @12PM
1st beta hcg 11/6@7am- 7.09
Progesterone-21.34
E2-128
Any hope this will be promising?

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Jouline

Hi Dr. I did an IUI insemination on Oct 17th and did my first hcg today Nov 6. My cycle is usually 29 day. My hcg test is 131 is that normal? (Last day of past period was Oct 11)

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Lina

Hi,
We had a perfect blastocyst transferred oct 12. HCG 9 days later was 109, then at 12 days it was 296, and 16 days after transfer it was 1600. Is there high chance of viable pregnancy based on these numbers? I have very few symptoms, now 6+2, and very anxious.

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Lina

Thank you for your quick reply. You think the numbers look good?

I am so scared, the few symptoms I have (slightly tender breasts and slightly cramping, like in periode) keep coming and going.

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Allie

Hi Dr. Sher

I had my first HCG at 9 DPT 127.8 then second HCG at 11 DPT 388.1. PSG normal 6AA. I have a history of chemical miscarriages. All my other previous chemicals had very low HCGs. Do these numbers look promising for a good pregnancy?

Thanks!

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Dr. Geoffrey Sher

Not looking very promising…I am afraid! Repeat the beta in 2 days and hope for the best.

Sorry!

Geoff Sher

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Angela

My HCG is 25 today—9 days past 5 day transfer. An FET. The clinic said it is unlikely to be viable. Would you agree?

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Dr. Geoffrey Sher

I respectfully do not agree. This could be a viable pregnancy. Repeat the test in n2 days to see if it doubles.

Geoff Sher

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georgia

i had my first beta at 10dp5dt and it was 170
my second was 47 hours later and it was 288.9
I had two early blastocysts transfed
is it still any hope for me?

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lorraine

Good morning Dr Sher
I did a beta blood test and hcg was 0.5miu/ml after4. 75 days after 5 day transfer. My clinic is saying its way to early.
Do you think i still have a chance of getting a positive result?

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Priscilla

Hi Dr Sher,

I had a 5-day FET on 10/16, first hcg level was 52 on 10/25, 83 on 10/28, 234 on 10/30 and 689 on 11/1

The numbers seem very low, do I still have hope for an ongoing normal pregnancy?

I am very concerned.

Thank you

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Dr. Geoffrey Sher

Frankly, I am not very concerned. Frankly, I am even cautiously optimistic.

Good luck!

Geoff Sher

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Claudia

Hi, I had a 2 5 day blastocysts transferred. My hcg numbers are were 32 at 5 dpt, 114 at 7dpt, 292 at 9dpt and 670 at 11dpt. I know that they are doubling and that is what is important, but do these numbers generally look ok ? The normal range is so varied that it’s hard to get a feel for what is good. Does normal doubling mean its more likely to be a singleton? thanks!

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