3chords
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Hi all,
I'm just cross-posting this from the Pregnancy Test subforum as I think some people here may appreciate the information but don't head out there much, heaven knows I didn't want to look at other pee sticks when I was in the middle of my many treatment cycles (and still am!).
This is just a collection of information that I put together over the years of TTCing. I think there is a lot of benefit in scientific fact, mostly because when I was going through any one of my multiple losses well-meaning people would sometimes tell me all sorts of things about betas and heartbeats and how darkness of a test line doesn't matter...and it drove me crazy because I knew otherwise in my heart. So I set out to see what the research actually says. Hope it helps anyone who is looking for some answers.
Beta HCG Rates of Increase
Not as much research exists on this topic but there are a few things that carry consensus, summarized below.
Doubling rate = 100% rise. The closer you get to 100% rise in 48 hours, the better but a 2009 Shamonki et al. study showed that there is no further enhancement in live birth rates with increases greater than 100%. Meaning that if your beta just doubles, its good enough, your pregnancy outcome isnt going to be any better if it triples or quadruples.
A 2016 Sung et al. study looked at doubling rates between 12DPO and 14DPO for fresh and frozen IVF cycles. In fresh cycles, if your beta increased by a factor of at least 2.56 between 12DPO and 14DPO, the odds of ongoing pregnancy were about 74% - meaning for example if your beta at 12 DPO was 50, a 2.56 fold rise would be 128 at 14DPO. In frozen cycles, the beta would have to increase by 2.38 to give you an 82% chance of ongoing pregnancy.
Beta HCG thresholds using Clearblue Digital With Weeks Indicator
ClearBlue had to file a 510(k) data sheet with the Food & Drug Administration. It is available online and it states the thresholds of detection for various levels. I have summarized below, you will see two numbers for each indicator the first number indicates the LOWEST possible beta that will show you a particular result and the second number indicates the lowest beta at which ALL women in the study got the particular result.
1-2 weeks: low threshold 10.2; all women 17.7. Meaning no woman with a beta lower than 10.2 got a positive pregnancy 1-2 weeks result and no woman with a beta of 17.7 or higher got a negative pregnancy result.
2-3 weeks: low threshold 121; all women 504.
3+ weeks: low threshold 2103; all women 4176.
Pregnancy Outcomes Based on Early Beta
Importance of high early betas
o The truth is that early implantation is extremely important in ongoing pregnancy and live births. Literally every single study out there supports this fact. It may be surprising to many people just how high the betas need to be early on.
o A 2016 Chen et al. study looked at betas at 10DPO/7dp3dt/5dp5dt and concluded that women with a beta >26.6 on this day had a 76% chance of ongoing pregnancy.
o A 2016 Sung et al. study looked at betas at 12DPO and 14DPO as well as the
o The most comprehensive of studies appears to be a 2001 Poikkeus et al. study that looked at beta HCG levels at 12dp3dt (equivalent of 15DPO or 10dp5dt). The conclusions are very interesting. Notably, on that day no ectopic pregnancy had a beta that was higher than 86 and no chemical pregnancy had a beta that was higher than 106. Ive put down the rough number sets for: miscarriage/singleton/twin pregnancy % odds on this day as follows (when they do not add up to 100 its due to the rest being ectopics or chemicals): Beta 5-14: 10/4/0; Beta 15-28: 25/1/0; Beta 29-45: 32/30/1; Beta 45-66: 31/45/3; Beta 67-86: 30/57/5; Beta 87-106: 15/75/10; Beta 107-131: 23/67/20; Beta 132-169: 5/75/15; Beta 170-220: 4/66/30; Beta 221-683: 5/45/50.
o Lessons learned: Miscarriage rates are very low (5%) and ectopic and chemicals are nonexistent at a beta of 132 or higher at 15DPO.
Vanishing Twin
On average, the beta of singletons, twins and vanishing twins will at least double in 48 hour period. In a 2013 study by Brady et al. the average rate of increase of beta in vanishing twins is lower (114%) than singletons (128.8%) and twins (125.4%).
Lesson learned: while beta hcg levels with vanishing twins rise at a slightly slower rate than singletons and twins it DOES double, therefore abnormal beta hcg level increases should NOT be attributed to a vanishing twin.
Ectopic Pregnancies
Studies agree that no single level of beta HCG is diagnostic of ectopic pregnancy and monitoring HCG levels is also not particularly predictive as they vary widely. In a 2016 Surampudi et al. study of 48 hour beta HCG repeats in women who had ectopic pregnancies and a beta of less than 1500 at the time of blood draws showed the following: (1) 22.5% of women plateaued had neither an increase or decrease; (2) 26.8% had a decrease of 15% or more; and (3) 47.9% had an increase of 15% or more and of this group almost ¼ of the women had a doubling which would be considered normal.
Lesson learned: ectopic pregnancies can only reliably be diagnosed via ultrasound.
Early Fetal Heartbeats
There is scientific consensus that slow embryonic heart rate in the first trimester is an indicator of poor pregnancy outcome.
Doubilet et al. have published a number of studies looking at very early embryonic heart rates of 6-7 weeks gestation. The odds of miscarriage based on heart rates of embryos which are 6+2 weeks of gestation or younger are: 78% if heart rate is less than 80bpm, 46% if heart rate is 80-89bpm, 17% if heart rate is 90-99bpm and 9% if hear rate is >100bpm. The odds of miscarriage based on heart rates of embryos that are 6+3 to 7 weeks of gestation are: 78% if heart rate is <100bpm, 46% if heart rate is 100-109bpm, 17% if heart rate is 110-119bpm and 9% if heart rate is >120bpm.
Lesson learned: embryonic heart rates are highly predictive of pregnancy outcomes.
I'm just cross-posting this from the Pregnancy Test subforum as I think some people here may appreciate the information but don't head out there much, heaven knows I didn't want to look at other pee sticks when I was in the middle of my many treatment cycles (and still am!).
This is just a collection of information that I put together over the years of TTCing. I think there is a lot of benefit in scientific fact, mostly because when I was going through any one of my multiple losses well-meaning people would sometimes tell me all sorts of things about betas and heartbeats and how darkness of a test line doesn't matter...and it drove me crazy because I knew otherwise in my heart. So I set out to see what the research actually says. Hope it helps anyone who is looking for some answers.
Beta HCG Rates of Increase
Not as much research exists on this topic but there are a few things that carry consensus, summarized below.
Doubling rate = 100% rise. The closer you get to 100% rise in 48 hours, the better but a 2009 Shamonki et al. study showed that there is no further enhancement in live birth rates with increases greater than 100%. Meaning that if your beta just doubles, its good enough, your pregnancy outcome isnt going to be any better if it triples or quadruples.
A 2016 Sung et al. study looked at doubling rates between 12DPO and 14DPO for fresh and frozen IVF cycles. In fresh cycles, if your beta increased by a factor of at least 2.56 between 12DPO and 14DPO, the odds of ongoing pregnancy were about 74% - meaning for example if your beta at 12 DPO was 50, a 2.56 fold rise would be 128 at 14DPO. In frozen cycles, the beta would have to increase by 2.38 to give you an 82% chance of ongoing pregnancy.
Beta HCG thresholds using Clearblue Digital With Weeks Indicator
ClearBlue had to file a 510(k) data sheet with the Food & Drug Administration. It is available online and it states the thresholds of detection for various levels. I have summarized below, you will see two numbers for each indicator the first number indicates the LOWEST possible beta that will show you a particular result and the second number indicates the lowest beta at which ALL women in the study got the particular result.
1-2 weeks: low threshold 10.2; all women 17.7. Meaning no woman with a beta lower than 10.2 got a positive pregnancy 1-2 weeks result and no woman with a beta of 17.7 or higher got a negative pregnancy result.
2-3 weeks: low threshold 121; all women 504.
3+ weeks: low threshold 2103; all women 4176.
Pregnancy Outcomes Based on Early Beta
Importance of high early betas
o The truth is that early implantation is extremely important in ongoing pregnancy and live births. Literally every single study out there supports this fact. It may be surprising to many people just how high the betas need to be early on.
o A 2016 Chen et al. study looked at betas at 10DPO/7dp3dt/5dp5dt and concluded that women with a beta >26.6 on this day had a 76% chance of ongoing pregnancy.
o A 2016 Sung et al. study looked at betas at 12DPO and 14DPO as well as the
o The most comprehensive of studies appears to be a 2001 Poikkeus et al. study that looked at beta HCG levels at 12dp3dt (equivalent of 15DPO or 10dp5dt). The conclusions are very interesting. Notably, on that day no ectopic pregnancy had a beta that was higher than 86 and no chemical pregnancy had a beta that was higher than 106. Ive put down the rough number sets for: miscarriage/singleton/twin pregnancy % odds on this day as follows (when they do not add up to 100 its due to the rest being ectopics or chemicals): Beta 5-14: 10/4/0; Beta 15-28: 25/1/0; Beta 29-45: 32/30/1; Beta 45-66: 31/45/3; Beta 67-86: 30/57/5; Beta 87-106: 15/75/10; Beta 107-131: 23/67/20; Beta 132-169: 5/75/15; Beta 170-220: 4/66/30; Beta 221-683: 5/45/50.
o Lessons learned: Miscarriage rates are very low (5%) and ectopic and chemicals are nonexistent at a beta of 132 or higher at 15DPO.
Vanishing Twin
On average, the beta of singletons, twins and vanishing twins will at least double in 48 hour period. In a 2013 study by Brady et al. the average rate of increase of beta in vanishing twins is lower (114%) than singletons (128.8%) and twins (125.4%).
Lesson learned: while beta hcg levels with vanishing twins rise at a slightly slower rate than singletons and twins it DOES double, therefore abnormal beta hcg level increases should NOT be attributed to a vanishing twin.
Ectopic Pregnancies
Studies agree that no single level of beta HCG is diagnostic of ectopic pregnancy and monitoring HCG levels is also not particularly predictive as they vary widely. In a 2016 Surampudi et al. study of 48 hour beta HCG repeats in women who had ectopic pregnancies and a beta of less than 1500 at the time of blood draws showed the following: (1) 22.5% of women plateaued had neither an increase or decrease; (2) 26.8% had a decrease of 15% or more; and (3) 47.9% had an increase of 15% or more and of this group almost ¼ of the women had a doubling which would be considered normal.
Lesson learned: ectopic pregnancies can only reliably be diagnosed via ultrasound.
Early Fetal Heartbeats
There is scientific consensus that slow embryonic heart rate in the first trimester is an indicator of poor pregnancy outcome.
Doubilet et al. have published a number of studies looking at very early embryonic heart rates of 6-7 weeks gestation. The odds of miscarriage based on heart rates of embryos which are 6+2 weeks of gestation or younger are: 78% if heart rate is less than 80bpm, 46% if heart rate is 80-89bpm, 17% if heart rate is 90-99bpm and 9% if hear rate is >100bpm. The odds of miscarriage based on heart rates of embryos that are 6+3 to 7 weeks of gestation are: 78% if heart rate is <100bpm, 46% if heart rate is 100-109bpm, 17% if heart rate is 110-119bpm and 9% if heart rate is >120bpm.
Lesson learned: embryonic heart rates are highly predictive of pregnancy outcomes.
