What is a chemical pregnancy?

Girl holding a pregnancy test
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A chemical pregnancy is a medical term for a very early miscarriage. This type of loss usually occurs before or right around when a woman would expect her period. Many times it happens after a woman hs had a positive pregnancy test but soon after starts what she believes to be her period.

How common are chemical pregnancies?

This is actually fairly difficult to study. One study done measured miniscule amounts of hCG in the urine of healthy women with normal fertility who were trying to conceive.

They charted the cycles and the hCG results. According to this study, about 20% of pregnancies may be lost before a woman has even had a positive pregnancy test or when a pregnancy test would have been positive.  When you included the miscarriages for those pregnancies that were known, the total pregnancy loss rate from miscarriage was about 30% of the pregnancies or a third of pregnancies.

"I had never heard of a chemical pregnancy before," said April. "I had a positive pregnancy test and I called my midwife to make an appointment. They took all my information and set me up for an appointment. My period showed up two days later and when I called to cancel I joked about making a mistake with the pregnancy test. She is the one who said I probably hadn't made a mistake and explained what a chemical pregnancy was. I went in for a physical because I was due and we wanted to have a baby."

Has there been a rise in chemical pregnancies?

You may feel like you are hearing more about chemical pregnancies these days, that is most likely because of very early pregnancy testing at home.

These early pregnancy tests can give an accurate positive result before you expect your period. Then the pregnancy fails. Without these tests the woman would not have known she was even pregnant.

What causes a chemical pregnancy?

Chemical pregnancies are not the result of anything that you have done other than the standard list of risky things in pregnancy like drinking or doing drugs.

They can be caused by chromosomal disorders, hormonal issues, luteal phase defect (LPD), problems with the lining of the uterus, some infections or even structural abnormalities within the uterus, including fibroids

If you are concerned that your medical history or your social history (what you eat, drink, smoke, do, etc.) has to do with your chances of having a chemical pregnancy or miscarriage, be sure to talk to your doctor. You can even ask your annual exam or during a preconceptional visit. 

Will I have another chemical pregnancy?

While very unlikely, recurring chemical pregnancies need to be treated by your doctor or midwife. There may be some medicinal therapies that can be beneficial, depending on what your practitioner feels is the cause of your problems. Some treatments for recurrent miscarriage include hormone therapies, antibiotics, or even baby aspirin. Talking to your doctor or specialist will be helpful at determine the test and treatments that would be best for you and your family.


Promislow JHE, Baird DD, Wilcox AJ, and Weinberg CR. "Bleeding following pregnancy loss before 6 weeks' gestation." Human Reproduction 2007.

Wilcox AJ, Weinberg CR, O'Connor JF, Baird DD, Schlatterer JP. "Incidence of early loss of pregnancy." New England Journal of Medicine 1988.

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