What is a ‘chemical’ pregnancy?
Sometimes a positive pregnancy test never gets beyond that very pale, blue line.
The line doesn’t darken and become louder and clearer.
A scan never identifies an implanted embryo, an empty sac or an arrested development – and you might be left wondering whether you were ever really pregnant at all if there is no physical sign of the pregnancy on a scan.
And the answer is yes, you really were pregnant.
When an embryo attempts to implant, a biochemical is produced called human chorionic gonadotropin (hCG). This is the same biochemical that triggers a home pregnancy test to confirm pregnancy and the biochemical that is measured by a blood test to confirm pregnancy. If hCG is detected after the due date of your cycle, it means that something is attempting to implant – but until the pregnancy is confirmed via a scan, the presence of hCG doesn’t confirm that the implantation has been successful, or that the pregnancy is developing as expected.
And if you get to that scan and they can’t see any evidence of the pregnancy on the scan, then it will be diagnosed as ‘chemical’ because the only evidence that the pregnancy occurred was a chemical signature of the pregnancy.
(It is worth noting that if you have had an IVF cycle, it is important not to test before your test date as some cycles use a form of artificial hCG which might give a false positive if you test too early)
Various sources suggest that between 50-75% of miscarriages are from chemical pregnancies, and many of these go undetected, unrecognised.
Unless you are monitoring your cycle, you might miss the exact date of ovulation, so not realise the luteal phase has run for a few more days. You might shrug off that slightly heavier, late bleed as just one of those random things.
But when you are monitoring your cycle, a chemical pregnancy is rollercoaster of the emotions of excitement, despair and confusion.
So What Does A Chemical Pregnancy Mean For Your Fertility?
A chemical pregnancy does mean that something has tried to implant, the egg and sperm have combined to create an entity that is capable of trying to implant.
It means there was an egg released.
It means that sperm found the egg (in the case of natural pregnancy)
It means the sperm and egg fused to form an embryo.
It means the embryo reached the stage in development where it was able to attempt to implant.
For the prospect of future fertility, these are all milestones and that may come as some comfort.
So What Could Have Gone Wrong?
There are various reasons why a chemical pregnancy did not continue to develop as hoped.
Maybe the chosen site of implantation was not suitable, maybe the embryo found itself in a fallopian tube, on a small area of scar tissue, on an area of the uterus that was unable to accept the placenta properly.
Maybe the uterus was not quite ready (or over-ready) and not able to respond correctly to the attempted implantation.
Maybe there were chromosomal irregularities in the embryo that meant it has sufficient data to attempt to implant but was unable to take the next step.
Maybe the body just simply wasn’t able to provide the resources to the uterus, so the uterus was unable to respond correctly to support the implantation.
So What Next?
A chemical pregnancy can be seen as a good indicator of the potential for natural pregnancy, if taken as a sign that all was well and the only issue might have been a chromosomal issue – each month the egg and sperm will be different, so if everything else is working, it should only be a matter of time until one sticks.
If it is something that happens repeatedly, then I would start to wonder whether some further investigation into the uterine environment would be a good idea:
A 3D SIS scan to take a closer look at the uterine cavity
Microbiome testing to see if there are any signs of infection, pelvic inflammatory disease or other microbiome issues. Sometimes vaginal microbiome testing is enough, sometimes the EMMA or ALICE test are worth considering.
If the chemical pregnancies are from IVF, I would consider looking at sperm DNA fragmentation as this can raise the risk of embryos being created that don’t have the ability to implant properly.
If the chemical pregnancies are from IVF it might be time to consider the ERA test to check endometrial receptivity – some people respond at unusual rates to supplemented progesterone and the ERA can check whether your uterine lining is in the correct state for the chosen day of transfer. Although it has been suggested that measuring blood progesterone levels can give just as good an indicator without the invasive procedure.
A Final Word
A ‘chemical pregnancy’ is a pregnancy.
A miscarriage is a miscarriage.
A loss is a loss – whatever stage, whatever age.
It is so important to allow yourself to feel whatever you need to feel about a chemical pregnancy. Any pregnancy loss is hugely significant and will be accompanied by feelings of shock, grief, despair and fear. These emotions are all absolutely valid, this is not ‘just a chemical pregnancy’, this is a loss. A loss of hopes, a loss of dreams.
You may need time to recover from this, and support from your loved ones.
If you want to reach out for help, there are some amazing miscarriage support resources out there: