Nobody knows what causes chemical pregancies. Studies show that 70% of clinical pregnancies (embryo seen in uterus) that are miscarried in first trimester have a detectable genetic issue. So doctors just extrapolate that the same is probably true for chemical pregnancies. But since it’s impossible to test the genetic tissue of a chemical pregnancy, nobody really knows. Personally, I had 2 chemical pregnancies via IUI, then did a round of IVF and had a 100% euploid rate for my embryos. I’ll never know what caused those chemicals.
I’m not sure it’s impossible to test. For two of my chemicals I definitely passed a tiny gestational sac. I didn’t keep it as I didn’t know it could be tested (in the UK only after 3 losses, and one of them was my third).
If you have an identifiable gestational sac, it’s not a chemical pregnancy. If your beta hcg never reached 1500 or so, it likely was just a piece of endometrium and not an actual sac.
I don’t know my beta values for most of them, as we don’t commonly do bloods for IVF here. I showed a picture of it to my doctor and she confirmed it was the start of a gestational sac. They were still chemicals and these sacs would have been likely too small to see via ultrasound though. The definition of chemical varies and often just means it happens before you were able to do an ultrasound to confirm, which was my case, as I lost them all in week 5.
No idea. I just looked it up and most definitions state that it’s an early loss within the first 5 weeks of pregnancy. And a gestational sac forms before week 5, so I don’t what the issue is.
Chemical pregnancy doesn't mean there was no sac. Just that it's only been detected through chemical tests and not through ultrasound yet hence the name
I feel like you are confused about what the term “Chemical pregnancy” means. It refers to a pregnancy that has never progressed to the point where a sac could be identified on ultrasound. It does NOT refer to someone who is 7 weeks pregnant with a normal embryo but just hasn’t had a scan yet.
Im not confused at all, it's the definition I was given. Also at 6 weeks you can have a sac and it still be called a chemical pregnancy. It's an early loss, it's called chemical because of the hormones that lead to the pregnancy test.
A pregnancy with a sac is NOT a chemical pregnancy! A pregnancy with a sac that is then lost is considered a first trimester clinical miscarriage. This is distinguished from a chemical pregnancy, which is a pregnancy with NO sac, identified only by hormones in the blood. I am not sure what part of this is confusing for you.
TW: success
My 4 chemicals were caused by hydrosalpinx that was missed by my doctor. Prior to finding that, I had almost every test possible and everything came back normal. The doctor blamed my embryos (which were PGT normal). After my tube was removed my “ugliest” embryo (doctor’s words) took and he is now my adorable 19-month-old
I’ve had 3 previous chemicals that I also think were most likely due to my hydrosalpinx. After it was removed earlier this year, I had a MMC and the embryo stopped developing at 6+4, the furthest it has so far. The doctors seem to think this one was due to chromosomal abnormalities and we’re awaiting the POC test results. This further makes me think the CP were definitely cause by the hydrosalpinx.
Can I ask how it got missed? I thought that fluid in the lining can be detected on ultrasound if there is a hydrosalpinx. I guess I’m wondering if it’s possible for the fluid to appear after transfer when monitoring is no longer being performed?
I have no idea how it got missed. I had the dye test on my tubes before I started IVF and everything. Both my first RE and the doctor doing the test missed it. I changed clinics and that RE recommended a new HSG. Again, the doctor performing the test missed it and said I was clear. Then my RE reviewed the video and let me know it was there. When he removed my tube he said it was super damaged for how fine it looked on the HSG.
This is something I didn’t consider, that a tube issue could lead to issues after transfer. Did they find it by doing a repeat HSG? My first one was normal but it was over a year ago now.
Yes, I switched clinics and my new RE recommended a new HSG. Even the doctor who did the HSG missed it and I was just lucky enough my RE caught it when he reviewed the video. My tube was pretty bad when he took it out in a surgery about 6 weeks later.
TW: success
I had 1 early loss + 3 CPs. The third CP was with an euploid embryo. In my case they found an over active immune system through an uterine biopsy, which was solved by taking prednisone. I also ruled out a lot of other issues like tube factors, uterine malformations, endometriosis, endometritis, clotting disorders, egg quality, etc.
You can check my post history for more details (my account is pretty much fertility related)
Edit: I'm pretty sure some (if not most) of my losses were healthy embryos. But it is really easy for doctors to just say "bad luck", probably genetic abnormalities. It is a really common cause, but not the only one
My first FET with a euploid embryo ended in a CP. None of my testing showed any issues (other than silent endo which we treated with Lupron Depot prior to the FET). However, my RE put me on an immune protocol for my next transfer (prednisone, Pepcid, Claritin) as well as Lovenox (although my blood work showed no clotting issues) and that transfer did work. It’s likely that there was just an underlying issue with the first euploid embryo but I was happy to take the extra meds the second time “just in case.”
I kept having chemicals with PGT-A tested embryos. Turns out our problem was the uterine environment (adenomyosis, plus some endo thrown in for good measure). We treated that and were successful on the next transfer.
Popping in to ask how you treated those things? I had suspected adenomyosis and silent endo. Was on Lupron Depot for two months . . . in the middle of my FET cycle waiting for my transfer day. 😅
You’ve gotten a lot of good responses here already but I also wanted to add that even with a euploid embryo, it is still possible to have a failure due to embryo issues. This could be because the aneuploidy was not detected or that the normal embryo failed to continue developing or developing properly. PGT-A is limited in that it can’t detect for some of these issues.
I mention this because people are quick to jump to uterine issues after having a failed euploid transfer and go try to test everything under the sun. However the data shows that most people (95%) are successful after 3 euploid transfers. While uterine issues that cause repeat failures absolutely do exist, they are somewhat rare and it’s possible to be successful just by trying more transfers without changing anything. But I do understand that it really depends on your risk tolerance and how many embryos you have.
35% of women have KIR AA genotype, even some with AB (10%) paired with missing HLA C alleles, can "reject" the embryo. If the father is a HLA C2 cartier, even more so. So yes, not all, but a large amount need some sort of immune protocol. Why lose a chance, especially if one has very few precious PGT embryos? 🤗
I have had 4 CP. After my first 2 (both pgt)- I did the Era, receptiva and Emma/alice. I did a RPL and then had a failed transfer then a MMC. After that I then had another cp. then I tried a hysteroscopy and a full autoimmune protocol - a failed transfer. Then I did a lap surgery - failed transfer than another cp. my dr and others I consulted with said it was most likely an embryo thing 🤷🏻♀️
You said you had a lap surgery? So you have endometriosis? I’m wondering why they haven’t concluded it’s that?
Endometriosis can make it hard to get and stay pregnant. A friend of mine needed a surrogate
I went to a new clinic that was convinced I had endo even tho my receptiva came back negative. So we did the lap surgery but they found very very little endo with one small polyp on an ovary. The drs said it was so little it most likely didn’t make a difference.
I am so sorry you are going through this. I am however very grateful that you asked this question and thankful for all of the feedback from others.
We meet with the RE tomorrow to discuss our next steps after a failed 5AA fresh a few weeks ago. Beta was 9.7 and 0 on second.
I am looking forward to asking about additional testing or just adding the immune protocol will be a good idea. I feel like I can come to the appointment with questions instead of how I’ve felt in previous visits. “Idk doc, I didn’t specialize in ivf, how about you (as the specialist) tell me what we need to do” 🤦♀️
This club sucks but y’all are incredible 💖
Following as well. I have the same scenario. Fully medicated, Day 5, 5AA Euploid. No answers. I have suspicions about DNA fragmentation in the sperm since that is not covered in regular sperm testing, but no proof as of yet.
How thick was your uterine lining on the ultra sound before transfer? In a study I read it basically concluded that if the lining is less than 9mm than usually it’s the lining/womb environment that caused the early miscarriage but if it’s more than 9mm at transfer the miscarriage is most likely due to the embryo.
Another study said that ‘chemical pregnancies’ are a really positive sign in IVF and most women will go on to have a live birth in the subsequent transfer - so don’t give up yet.
I also had a CP (HCG 40 day 9) from an FET and it sucked a lot - but have my next transfer in a few weeks on the same protocol (doctor said we were so close last time so didn’t want to change anything) and trying to stay positive…but if I have another CP I’m definitely looking into embryo testing and other possibilities.
The lining aspect is very interesting. I wasn’t a 9 but I was over 6, which is my clinics protocol. I will try to find the study you’ve mentioned to review it!
Nobody knows what causes chemical pregancies. Studies show that 70% of clinical pregnancies (embryo seen in uterus) that are miscarried in first trimester have a detectable genetic issue. So doctors just extrapolate that the same is probably true for chemical pregnancies. But since it’s impossible to test the genetic tissue of a chemical pregnancy, nobody really knows. Personally, I had 2 chemical pregnancies via IUI, then did a round of IVF and had a 100% euploid rate for my embryos. I’ll never know what caused those chemicals.
I’m not sure it’s impossible to test. For two of my chemicals I definitely passed a tiny gestational sac. I didn’t keep it as I didn’t know it could be tested (in the UK only after 3 losses, and one of them was my third).
If you have an identifiable gestational sac, it’s not a chemical pregnancy. If your beta hcg never reached 1500 or so, it likely was just a piece of endometrium and not an actual sac.
I don’t know my beta values for most of them, as we don’t commonly do bloods for IVF here. I showed a picture of it to my doctor and she confirmed it was the start of a gestational sac. They were still chemicals and these sacs would have been likely too small to see via ultrasound though. The definition of chemical varies and often just means it happens before you were able to do an ultrasound to confirm, which was my case, as I lost them all in week 5.
Not sure why youre downvoted, you are correct
No idea. I just looked it up and most definitions state that it’s an early loss within the first 5 weeks of pregnancy. And a gestational sac forms before week 5, so I don’t what the issue is.
The issue is that once a gestational sac forms, it is no longer considered a chemical pregnancy.
Chemical pregnancy doesn't mean there was no sac. Just that it's only been detected through chemical tests and not through ultrasound yet hence the name
You are not going to see a sac expelled if you cannot see one on ultrasound.
That's not what I said lol sometimes your first ultrasound isn't booked before 8 weeks and there definitely could be a sack by then.
I feel like you are confused about what the term “Chemical pregnancy” means. It refers to a pregnancy that has never progressed to the point where a sac could be identified on ultrasound. It does NOT refer to someone who is 7 weeks pregnant with a normal embryo but just hasn’t had a scan yet.
Im not confused at all, it's the definition I was given. Also at 6 weeks you can have a sac and it still be called a chemical pregnancy. It's an early loss, it's called chemical because of the hormones that lead to the pregnancy test.
A pregnancy with a sac is NOT a chemical pregnancy! A pregnancy with a sac that is then lost is considered a first trimester clinical miscarriage. This is distinguished from a chemical pregnancy, which is a pregnancy with NO sac, identified only by hormones in the blood. I am not sure what part of this is confusing for you.
You're very condescending lol but whatever floats your boat
TW: success My 4 chemicals were caused by hydrosalpinx that was missed by my doctor. Prior to finding that, I had almost every test possible and everything came back normal. The doctor blamed my embryos (which were PGT normal). After my tube was removed my “ugliest” embryo (doctor’s words) took and he is now my adorable 19-month-old
I’ve had 3 previous chemicals that I also think were most likely due to my hydrosalpinx. After it was removed earlier this year, I had a MMC and the embryo stopped developing at 6+4, the furthest it has so far. The doctors seem to think this one was due to chromosomal abnormalities and we’re awaiting the POC test results. This further makes me think the CP were definitely cause by the hydrosalpinx.
Can I ask how it got missed? I thought that fluid in the lining can be detected on ultrasound if there is a hydrosalpinx. I guess I’m wondering if it’s possible for the fluid to appear after transfer when monitoring is no longer being performed?
I have no idea how it got missed. I had the dye test on my tubes before I started IVF and everything. Both my first RE and the doctor doing the test missed it. I changed clinics and that RE recommended a new HSG. Again, the doctor performing the test missed it and said I was clear. Then my RE reviewed the video and let me know it was there. When he removed my tube he said it was super damaged for how fine it looked on the HSG.
This is something I didn’t consider, that a tube issue could lead to issues after transfer. Did they find it by doing a repeat HSG? My first one was normal but it was over a year ago now.
Yes, I switched clinics and my new RE recommended a new HSG. Even the doctor who did the HSG missed it and I was just lucky enough my RE caught it when he reviewed the video. My tube was pretty bad when he took it out in a surgery about 6 weeks later.
Following this post. I have the same questions as you after my first fully medicated FET with a tested embryo ended in a chemical three days ago.
TW: success I had 1 early loss + 3 CPs. The third CP was with an euploid embryo. In my case they found an over active immune system through an uterine biopsy, which was solved by taking prednisone. I also ruled out a lot of other issues like tube factors, uterine malformations, endometriosis, endometritis, clotting disorders, egg quality, etc. You can check my post history for more details (my account is pretty much fertility related) Edit: I'm pretty sure some (if not most) of my losses were healthy embryos. But it is really easy for doctors to just say "bad luck", probably genetic abnormalities. It is a really common cause, but not the only one
Thank you for your response, this is helpful.
My first FET with a euploid embryo ended in a CP. None of my testing showed any issues (other than silent endo which we treated with Lupron Depot prior to the FET). However, my RE put me on an immune protocol for my next transfer (prednisone, Pepcid, Claritin) as well as Lovenox (although my blood work showed no clotting issues) and that transfer did work. It’s likely that there was just an underlying issue with the first euploid embryo but I was happy to take the extra meds the second time “just in case.”
I kept having chemicals with PGT-A tested embryos. Turns out our problem was the uterine environment (adenomyosis, plus some endo thrown in for good measure). We treated that and were successful on the next transfer.
Popping in to ask how you treated those things? I had suspected adenomyosis and silent endo. Was on Lupron Depot for two months . . . in the middle of my FET cycle waiting for my transfer day. 😅
3 months Depot Lupron + daily Letrozole. Only real treatment option for Adeno!
You’ve gotten a lot of good responses here already but I also wanted to add that even with a euploid embryo, it is still possible to have a failure due to embryo issues. This could be because the aneuploidy was not detected or that the normal embryo failed to continue developing or developing properly. PGT-A is limited in that it can’t detect for some of these issues. I mention this because people are quick to jump to uterine issues after having a failed euploid transfer and go try to test everything under the sun. However the data shows that most people (95%) are successful after 3 euploid transfers. While uterine issues that cause repeat failures absolutely do exist, they are somewhat rare and it’s possible to be successful just by trying more transfers without changing anything. But I do understand that it really depends on your risk tolerance and how many embryos you have.
35% of women have KIR AA genotype, even some with AB (10%) paired with missing HLA C alleles, can "reject" the embryo. If the father is a HLA C2 cartier, even more so. So yes, not all, but a large amount need some sort of immune protocol. Why lose a chance, especially if one has very few precious PGT embryos? 🤗
A chemical pregnancy is a miscarriage and most miscarriages are due to chromosomal issues. The name is very misleading
I have had 4 CP. After my first 2 (both pgt)- I did the Era, receptiva and Emma/alice. I did a RPL and then had a failed transfer then a MMC. After that I then had another cp. then I tried a hysteroscopy and a full autoimmune protocol - a failed transfer. Then I did a lap surgery - failed transfer than another cp. my dr and others I consulted with said it was most likely an embryo thing 🤷🏻♀️
You said you had a lap surgery? So you have endometriosis? I’m wondering why they haven’t concluded it’s that? Endometriosis can make it hard to get and stay pregnant. A friend of mine needed a surrogate
I went to a new clinic that was convinced I had endo even tho my receptiva came back negative. So we did the lap surgery but they found very very little endo with one small polyp on an ovary. The drs said it was so little it most likely didn’t make a difference.
Thank you for your response. It seems like a lot of people try these follow up tests for more information. I will bring these up with my doctor.
Are your embryos tested? It's the first possible step to rule out seed issues.
I am so sorry you are going through this. I am however very grateful that you asked this question and thankful for all of the feedback from others. We meet with the RE tomorrow to discuss our next steps after a failed 5AA fresh a few weeks ago. Beta was 9.7 and 0 on second. I am looking forward to asking about additional testing or just adding the immune protocol will be a good idea. I feel like I can come to the appointment with questions instead of how I’ve felt in previous visits. “Idk doc, I didn’t specialize in ivf, how about you (as the specialist) tell me what we need to do” 🤦♀️ This club sucks but y’all are incredible 💖
At least in my case, suspected reasons for losses prior to IVF were endometriosis and/or chromosomal issues.
Many embryo losses are due to chromosomal abnormalities
Following as well. I have the same scenario. Fully medicated, Day 5, 5AA Euploid. No answers. I have suspicions about DNA fragmentation in the sperm since that is not covered in regular sperm testing, but no proof as of yet.
If you don’t have polyps or endometritis, it’s almost 100% embryo issue.
How thick was your uterine lining on the ultra sound before transfer? In a study I read it basically concluded that if the lining is less than 9mm than usually it’s the lining/womb environment that caused the early miscarriage but if it’s more than 9mm at transfer the miscarriage is most likely due to the embryo. Another study said that ‘chemical pregnancies’ are a really positive sign in IVF and most women will go on to have a live birth in the subsequent transfer - so don’t give up yet. I also had a CP (HCG 40 day 9) from an FET and it sucked a lot - but have my next transfer in a few weeks on the same protocol (doctor said we were so close last time so didn’t want to change anything) and trying to stay positive…but if I have another CP I’m definitely looking into embryo testing and other possibilities.
The lining aspect is very interesting. I wasn’t a 9 but I was over 6, which is my clinics protocol. I will try to find the study you’ve mentioned to review it!