What Is Chemical Pregnancy? Symptoms, Causes, Diagnosis, and Treatment
By Stacey ColinoMedically Reviewed by Kara Leigh Smythe, MD
Reviewed:
Medically Reviewed
A chemical pregnancy is a very early miscarriage that occurs when an egg is fertilized but doesn’t fully implant in the uterus. The pregnancy is lost before the fifth week.Chemical pregnancies (also known as biochemical pregnancies) are very common.
What’s more, research has found that up to one in four pregnancies is lost even before a woman misses her period or has symptoms of pregnancy — these are chemical pregnancies.
The term “chemical pregnancy” refers to a positive result on a blood or urine test that gauges the presence of a hormone, human chorionic gonadotropin (hCG), to detect a pregnancy. But many women who have a chemical pregnancy don’t even realize they’re pregnant because the loss is so early; they may not have taken a pregnancy test,had any pregnancy symptoms, or even missed a period. They may simply have a late period that’s a bit heavier than usual.
Common Questions & Answers
What is a chemical pregnancy?
A chemical pregnancy is a very early miscarriage. It’s called a chemical pregnancy because it’s confirmed by a blood or urine test that measures the amount of the pregnancy hormone human chorionic gonadotropin (hCG) in your body.
What are the signs of a chemical pregnancy?
Many women who have a chemical pregnancy don’t realize they’re pregnant. The loss happens so early on, there might not be any symptoms. But you might experience a late period, cramps, and heavy period-like bleeding that sometimes includes clotting.
How do I know if I had a chemical pregnancy?
You may have period-like symptoms, but the only way to tell for sure whether you’ve been pregnant is a blood or urine test that detects the presence of the pregnancy hormone hCG.
How long does chemical pregnancy last?
In a chemical pregnancy, the pregnancy is lost before the fifth week.
What is the most common reason for a chemical pregnancy?
Most miscarriages, including chemical pregnancies, are caused by chromosomal abnormalities that prevent the fetus from developing normally. In assisted pregnancies, damage that occurs to the embryo during the freezing process may result in a chemical pregnancy.
Signs and Symptoms of Chemical Pregnancy
Because a chemical pregnancy occurs so soon after conception, some women may not be aware they’re pregnant. Those who do know that they’re pregnant or suspect they’ve had a chemical pregnancy may experience the following symptoms:
- A late period
- Heavy period-like bleeding, perhaps with clots
- Menstrual-like cramps
Your doctor can confirm that you had a chemical pregnancy with a urine test or blood test to check the level of hCG in your body.
Causes and Risk Factors of Chemical Pregnancy
Most miscarriages, including chemical pregnancies, are caused by chromosomal abnormalities that prevent the fetus from developing normally.In an assisted pregnancy that uses frozen embryos, damage that occurs to the embryo during the freezing process may result in a chemical pregnancy; as many as 20 percent of pregnancies involving the transfer of frozen embryos result in a chemical pregnancy.
Other causes can include:
- An insufficient (too thin) uterine lining
- A problem with DNA in the sperm
- Low hormone levels
- Infections
- Pregnancy with an IUD in place
Meanwhile, certain conditions can put a woman at increased risk for a chemical pregnancy. These include being 35 or older, having an untreated clotting disorder or thyroid condition, or having another poorly controlled chronic medical condition such as diabetes.
How Is Chemical Pregnancy Diagnosed?
Sometimes a woman will take a home pregnancy test and get a positive result, but then she’ll have a late period or discover through a pregnancy test at the doctor’s office that there’s no pregnancy. Your doctor can confirm that you had a chemical pregnancy with a urine or blood test to check the level of hCG in your body. In other instances, women may not even know they’ve been pregnant; they may think their period is simply late.
Prognosis of Chemical Pregnancy
In many cases, once your menstrual cycle normalizes after the early pregnancy loss, you can try to get pregnant again whenever you and your partner feel ready.If you have a medical condition (such as diabetes or a thyroid disorder) that may have contributed to a chemical pregnancy, getting it properly treated may help improve your chances of conceiving a viable pregnancy in the future.
Duration of Chemical Pregnancy
By definition, a chemical pregnancy occurs before the fifth week of pregnancy; it’s a very early miscarriage, in other words. The bleeding and cramping may last for a few days.
Treatment and Medication Options for Chemical Pregnancy
Very early pregnancy losses generally don’t require treatment, but if you think you have experienced one, be sure to tell your healthcare practitioner.If a medical condition may have contributed to a chemical pregnancy, getting it properly treated can help you improve your chances of conceiving a viable pregnancy and having a healthy baby in the future.Otherwise, once your menstrual cycle normalizes, you can try to get pregnant again whenever you feel ready.
Complications of Chemical Pregnancy
There aren’t usually any physical complications of chemical pregnancy, aside from cramping and sometimes heavier-than-usual bleeding. In rare instances, women may experience very heavy bleeding or hemorrhaging after a chemical pregnancy, which can lead to anemia; this requires medical attention.
RELATED: Early Pregnancy Loss May Trigger Post-Traumatic Stress Symptoms
But keep in mind that any kind of miscarriage can be upsetting, especially if you were trying to conceive or were excited about a positive pregnancy test or went through fertility treatment. As a result, you may experience stress-related symptoms or mood changes. Some women find that early pregnancy loss can trigger post-traumatic stress symptoms, such as intrusive or unwanted thoughts about the pregnancy loss, nightmares or flashbacks, hyperarousal, and avoidance of anything that reminds women of their loss.
Be sure to give your body and your mind ample time to recover from the loss.Whatever your feelings are, accept them and allow yourself time to fully process them, perhaps with support from friends, family members, or support groups.
Research and Statistics: How Many People Have a Chemical Pregnancy?
Chemical pregnancies are extremely common — as many as one-third of all pregnancies may be chemical pregnancies, and up to 22 percent of IVF pregnancies may be chemical pregnancies.
But in many cases, women don’t even know they were pregnant because the pregnancy loss occurs so early.
Related Conditions and Causes of Chemical Pregnancy
Certain medical conditions can put a woman at increased risk of a chemical pregnancy. These include an untreated clotting disorder or thyroid condition, or another poorly controlled chronic medical condition such as diabetes.In an assisted pregnancy that uses frozen embryos, damage that occurs to the embryo during the freezing process may result in a chemical pregnancy;as mentioned above, as many as 22 percent of IFV pregnancies may be chemical pregnancies.
Resources We Love
To learn more about chemical pregnancies, check out the following websites.
The American College of Obstetricians and Gynecologists (ACOG)
ACOG is a go-to source for research-supported information about women’s reproductive health issues, including conception, pregnancy and pregnancy loss, and best practices for each of these issues.
A valuable source of information about various types of miscarriages and how they affect women physically and emotionally, this UK-based organization provides news and research updates and various support services.
Editorial Sources and Fact-Checking
- What Is a Chemical Pregnancy? What to Expect. August 13, 2021.
- Chemical Pregnancy vs. Miscarriage. MedicineNet. December 20, 2019.
- Annan JJ, Gudi A, Bhide P, et al. Biochemical Pregnancy During Assisted Conception: A Little Bit Pregnant. Journal of Clinical Medicine Research. August 2013.
- Prager S, Micks E, Dalton V. Pregnancy Loss (Miscarriage): Risk Factors, Etiology, Clinical Manifestations, and Diagnostic Evaluation. UpToDate. August 30, 2022.
- Chemical Pregnancy. Miscarriage Association.
- Farren J, Jalmbrant M, Falconieri N, et al. Posttraumatic Stress, Anxiety and Depression Following Miscarriage and Ectopic Pregnancy: A Multicenter, Prospective, Cohort Study. American Journal of Obstetrics & Gynecology. April 2020.
- Everything You Need to Know About Chemical Pregnancies. Natalist. September 23, 2020.
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