Understanding What a Chemical Pregnancy Is, and Isn't

Woman in bathroom, looking at pregnancy test, holding hand on stomach
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The earliest form of miscarriage. The word "chemical" refers to a pregnancy that is too early to confirm except through biochemical means. Home pregnancy tests and hCG blood tests will be positive, but the baby and gestational sac will not develop enough to be visible on an ultrasound. (When the ultrasound can confirm the pregnancy, it is called a "clinical" pregnancy.)

The term "chemical" pregnancy can be confusing.

In a chemical pregnancy, the sperm and egg do meet but, for various reasons, the fertilized egg does not implant properly in the uterus, resulting in an early miscarriage.

What Is a Chemical Pregnancy?

Chemical pregnancies, or very early miscarriages, are pregnancies that end so early that the only evidence of the pregnancy comes from hCG levels(pregnancy hormone levels. If you have a chemical pregnancy, you may receive a positive result on an early pregnancy test only to have your period show up on time or a few days late. In a chemical pregnancy, the bleeding is not actually menstrual blood - it's a miscarriage.

Some women who experience a chemical pregnancy may not even know they were pregnant in the first place. That's because the miscarriage and bleeding often occurs around the same time as a woman's regular menstrual period.

What Causes Them?

Chemical pregnancies may cause up to 75 percent of all miscarriages.

You might assume, then, that a lot is known about them. Unfortunately, chemical pregnancies happen so early that it's difficult to collect any tissue for analysis. Therefore, it's hard to know exactly why they happen.

Doctors suspect that the main culprit behind chemical pregnancies is random chromosome problems in the fertilized egg.

Chromosome abnormalities are believed to be the main reason for all first-trimester miscarriages.

The fact that these problems are random means that they probably won't happen again. They are not the result of "bad genes."

Most of the time, chemical pregnancies are one-time experiences. That means that your next pregnancy will probably not be a chemical pregnancy. There's actually a silver lining to chemical pregnancies, even though it probably doesn't feel like it when it happens: Your doctor might say that a chemical pregnancy is proof that you can become pregnant.

What to Do If It Happens to You

If you have a positive pregnancy test but then experience heavy bleeding, call your doctor right away. It could be a chemical pregnancy. The most common physical signs of a chemical pregnancy are heavy bleeding, cramps and passing tissue. There's nothing you can do to stop the pregnancy loss, and usually no treatment is needed. But it's still a good idea to keep your doctor informed.

Recurrent Chemical Pregnancies

If you're having recurrent chemical pregnancies, such as two or more in a row, it may be a good idea to talk to a doctor about this.

You should know that doctors vary heavily in their approach to dealing with recurrent chemical pregnancies that lack medical documentation. If you get to your doctor soon enough after a chemical pregnancy, he or she may be able to confirm that you lost a pregnancy. This can help ensure that you get the right tests to rule out medical problems and are referred to a fertility specialist, if needed.

There's also a way to confirm a chemical pregnancy at home. During or very soon after your bleeding, take a home urine test. Early in a pregnancy loss it may still register as positive. If you get a positive result, repeat the test a week later; if the second test is negative, you probably experienced a chemical pregnancy.

Visiting an infertility speciality could help your odds of having a successful pregnancy down the line.

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