If you’ve ever spent time on websites or online forums dedicated to trying to conceive, you may have seen the term “chemical pregnancy.” It’s kind of—OK, definitely—confusing. What exactly is a chemical pregnancy, and how might you know if you’ve had one? We talked to ob/gyns for the top facts you need to know.
1. A chemical pregnancy describes a miscarriage that happens so early on, you may not even know you conceived.
“‘Chemical pregnancy’ is just the name of a very early miscarriage,” Maura Quinlan, M.D., M.P.H., an assistant professor in the department of obstetrics and gynecology at the Northwestern University Feinberg School of Medicine, tells SELF. How early? Well, it’s hard to say.
A chemical pregnancy doesn’t happen within a definitive time frame in those 20 weeks. Instead, this term typically describes the experience of getting a positive pregnancy test very soon after a fertilized egg attaches to the uterine lining, but getting confirmation that you’re no longer pregnant soon after that.
2. You might find out about your chemical pregnancy when, after getting a positive pregnancy test result, you get your period or see your ob/gyn.
At-home pregnancy tests look for the presence of human chorionic gonadotropin (hCG), which is a hormone from your placenta (the organ that helps maintain and nourish a pregnancy). With a chemical pregnancy, you have enough hCG to get a positive pregnancy test result, but your levels will start to fall as you miscarry.
If you’re trying to conceive, you’re probably keeping really close tabs on your cycle, so you may take a test the second your period is late. Getting your period soon after you get a positive result can understandably be confusing and devastating. (Although, keep in mind that there are all sorts of non-period reasons why you might bleed a bit early on in pregnancy, like a vaginal tear.)
The other way you might discover a chemical pregnancy is if you go to the doctor. Every practice is different, but your doctor will typically want to see you anywhere between six and 10 weeks after your missed period, Jessica Shepherd, M.D., a minimally invasive gynecologist at Baylor University Medical Center at Dallas, tells SELF.
During that visit, your doctor will want to confirm your pregnancy, which may involve an ultrasound. If you’re what doctors call clinically pregnant, there will be a gestational sac in your uterus or, if you’re further along, an embryo or fetus with a heartbeat, Dr. Quinlan says. If you’ve had a chemical pregnancy, tests won’t detect any of this, she says.
You might also realize you’re miscarrying due to bleeding and cramping as your body passes the tissue, but these symptoms may not be that intense since it’s so early, Dr. Shepherd says.
3. Not every false-positive pregnancy test is due to a chemical pregnancy.
A false-positive pregnancy test (when you get a positive result but aren’t actually expecting) can happen for many reasons, including a chemical pregnancy. But it’s hard for doctors to say how many false positives are due to chemical pregnancies specifically, Dr. Shepherd says, since there are quite a few other reasons why you might see a positive result when you’re not clinically pregnant.
They include using an expired test, having an ectopic pregnancy (when a fertilized egg attaches somewhere outside of the uterus), being on a fertility medication that contains hCG, and having residual hCG in your system after you give birth or have a miscarriage, Dr. Shepherd says. Menopause (or the time right before it, known as perimenopause) can cause your pituitary gland to produce more hCG, which could lead to a false positive. There are even rare cases of people with chronic kidney disease having elevated hCG levels (the kidneys play a role in clearing hCG from your system).
At-home pregnancy tests are most accurate if you wait until a week after your missed period to take them, the Mayo Clinic explains, although that’s mainly about avoiding false negatives, since it allows your hCG to build to solidly detectable levels. But to avoid the (rare) prospect of a false positive, you should make sure the test isn’t expired and follow the instructions precisely. Sometimes people get false positives because they let the test sit too long, then see a faint “second line” that seemingly signals pregnancy when it’s really just a line where pee has started to evaporate.
4. It’s definitely possible to have a chemical pregnancy and not know it.
If you don’t take a pregnancy test, you might chalk any random chemical pregnancy-induced bleeding and cramping up to a late or irregular period and PMS, Dr. Shepherd says. This is why experts say miscarriage occurs in about 10-20 percent of known pregnancies; the true incidence rate may be even higher.
5. Although it describes a very real phenomenon, “chemical pregnancy” isn’t technically a medical term.
Calling it a chemical pregnancy (or sometimes a biochemical pregnancy) instead of a miscarriage “is really more semantics,” Whitney You, M.D., a maternal-fetal medicine specialist at Northwestern Medicine Prentice Women’s Hospital and Lake Forest Hospital, tells SELF. “This is very patient-driven terminology,” Dr. Shepherd adds.
In fact, ACOG doesn’t use the term, Jamila Vernon, an ACOG spokesperson, tells SELF. Instead, they (and many doctors) use the phrase “early pregnancy loss” to indicate any miscarriage in the first 13 weeks, including the extremely early ones people might describe as chemical pregnancies.
6. Like all miscarriages, chemical pregnancies typically happen because of chromosomal abnormalities.
Chromosomes are the structures inside cells that contain genes, and most cells have 23 pairs of chromosomes, making 46 total. Normal sperm and eggs should each have 23 chromosomes, but if either has an abnormal number, so will the resulting embryo, ACOG explains—and that can lead to a miscarriage. “The fact that any of us are here really is remarkable given all the things that have to happen for a pregnancy to work,” Dr. You says.
There are a few other potential factors that can raise the risk of miscarriage, such as being over 40, ACOG explains. The jury is still out on whether or not activities like smoking and drinking play a role in miscarriage, but of course it’s still good to avoid these because of the other harms they can cause to a developing fetus and baby.
And don’t worry: Doing things like working, exercising, and having sex do not cause miscarriages, ACOG says.
7. A chemical pregnancy usually doesn’t require any physical treatment.
The only reason why you’ll need physical treatment after a pregnancy loss is if any of the tissue stays in your uterus and needs to be removed. Given that a chemical pregnancy happens so early, it’s highly unlikely that you’ll need any of those treatments, Dr. Shepherd says.
8. If you’ve had a positive pregnancy test, you should talk to your doctor no matter what, especially if you experience bleeding or cramping afterward.
Your doctor will likely want to run a few tests to confirm your pregnancy, including blood tests and an ultrasound. If you did in fact have a chemical pregnancy, the ultrasound will allow your doctor to make sure all the tissue has passed.
If losing a wanted pregnancy has shattered you emotionally, that’s entirely normal. Your ob/gyn should be able to counsel you on getting pregnant again. If necessary, seeing a mental health professional may help you process your emotions surrounding a miscarriage.