35 hours hCG doubling time - is it normal?

lissy87

New member
This is my first pregnancy and even though I’m reading everything I find on the internet, I still feel confused about beta hCG rising times. There’s so much emphasis put on how it shouldn’t be too slow, but what about too fast? I just got results from my second blood test after 3 days (70,5 hours to be exact) and it looks like it’s doubling at the rate of approx. 35 hrs. The results were: 13 dpo - 100 mlU/ml and 16 dpo - 404,1 mlU/ml. Knowing that high betas are associated with e.g. Down’s syndrome, makes me worried. I’ll be 34 next month, so I feel extra aware that my odds of something being wrong are not the lowest :(
 
@lissy87 I don't think you have any reason to worry. With my son, I had a 29 hour doubling time from 15 to 18 DPO (17 hr doubling time from 12 DPO to 15 DPO). All was well. I went down the Downs/HCG rabbit hole then too. From what I could find, it's the HCG later in the first trimester and in comparison to other hormone levels that can indicate an issue.
 
@thenazarene I was just coming over here to say that all the studies I'm pulling from pubmed are showing higher HCG in late first trimester going into second trimester, not the initial first few weeks of pregnancy! Although, it's unlikely to be tested for HCG that late into pregnancy unless down syndrome is already suspected since you can do your NIPT by 10 weeks.

I'm starting to think that HCG alone is the worst indicator of a healthy pregnancy lol.
 
@katrina2017 I think it's part of the first trimester screening that some women get along with an NT scan rather than doing the NIPT. But I agree that while betas can give some peace of mind in early pregnancy and can indicate a possible ectopic before it becomes catastrophic, overall there's so much variability in "normal" levels and doubling times that it seems to create more anxiety in the end.
 
@lissy87 Average doubling at this stage is 30-72 hours, so yours is NOT "too fast." Also, there is little to do scientific data on "fast" doubling. And your betas are NOT ridiculously high. And HCG correlation with DS is done with numbers from late-1st trimester, not your gestation.

100 at 13dpo is LOVELY and your doubling time is beautiful and normal.
 
@leathamoll So far, so good. I got my betas drawn again a week later (23dpo) and it was close to 11k, which is again showing ~35h doubling time. My gynecologist thinks it’s completely fine and told me to not pay attention to it anymore as there’s such a wide range of betas results between different pregnancies. I already had two ultrasounds, one at 5w2 and there was a gestational sac and yolk sac. Then I had another one at 7w1 and we could hear strong heartbeat and the embryo measured 11 mm. As far as I understand, this is all as expected. Based on my last ultrasound the doctor has already felt comfortable to tell me the best dates for me to get my nuchal translucency scan. I told him I worry the betas can mean something like Down syndrome, but he told me (just like the whole internet, lol) it only may mean something like this later in the first trimester, when they’re doing the nuchal translucency scan and adding blood results to calculate your risks. Early betas are basically quite random and all over the place, unless really low or extremely high.
 
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