What Is a Chemical Pregnancy?

A Type of Early Miscarriage That Usually Goes Unnoticed

man consoling his wife or girlfriend.
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A chemical pregnancy is a term used to describe a very early miscarriage which occurs before the fifth week of gestation and well before the fetus can be visibly detected on an ultrasound.

A chemical pregnancy is believed to affect as many as 75 percent of all pregnancies. The majority of women who have had one never actually realize they’ve conceived since the only real symptom is a late period. A chemical pregnancy is sometimes revealed when an early pregnancy test shows a faint positive result but later returns a negative result in a week or two.

While a chemical pregnancy typically doesn't cause harm to a woman's body, it can still lead to feelings of deep sadness and grief.

Overview

Most chemical pregnancies are believed to occur because the fertilized egg had some sort of chromosomal abnormality that made it non-viable from the start. When the body recognizes this, it will naturally terminate the pregnancy soon after the egg implants. The loss will typically happen about a week after your regular period was due.

While the implantation itself is never actually completed, the cells of the fertilized egg will still produce enough the pregnancy hormone hCG (human chorionic gonadotropin) to elicit a positive pregnancy test result.

In a chemical pregnancy, the gestational sac will not be large enough to be visible on an ultrasound. As such, the only way to confirm the pregnancy is through blood tests. Hence, the term chemical pregnancy refers to the biochemical means of diagnosis.

By contrast, a clinical pregnancy is one in which either a fetal heartbeat is detected or there is visual evidence on an ultrasound.

Chemical pregnancies are most often identified in women who are undergoing in vitro fertilization (IVF). The heightened anticipation of a pregnancy during IVF may lead some couples to test more frequently and earlier than those conceiving naturally.

Symptoms and Signs

A chemical pregnancy usually does not have any symptoms other than late menstruation. While some might expect that the menstrual bleeding would heavier than usual with a chemical pregnancy, it is often the same as a normal period or even lighter. In some cases, a woman may experience more cramping.

Because the pregnancy hormone levels are present but low in a chemical pregnancy, you wouldn't normally experience any of the other common signs of early pregnancy , such as fatigue or nausea.

Conceiving Afterwards

Chemical pregnancies happen early enough that they generally have little effect on a woman’s body. If one happens, there is usually nothing barring the couple from trying again immediately.

The good news is that if you have had a miscarriage of this sort, the chances are high that your next pregnancy will be normal. Even if you have had more than one miscarriage, your chances are still very good, but you may need to see a doctor to order tests to identify any possible causes of the recurrent miscarriage. Often times, these causes can be treated and the pregnancy can proceed without event.

Grieving

A chemical pregnancy can place a woman in a unique situation from a grieving perspective.

In some cases, a woman will feel little sadness about the loss, whereas others may be completely devastated.

While feelings of sadness and depression are not uncommon, women facing these emotions will often feel isolated in their grief. People may be reluctant to acknowledge the loss and may even suggest that it is unreasonable to feel this way because it wasn’t a "real baby.”

Regardless of what anyone says, a miscarriage is still a miscarriage. You neither have to justify your grief nor compare it to anyone else’s loss. It is a loss from which you may need time to recover. Give it time, and reach out to others who you believe will truly support you.

On the other hand, it is just as OK not to feel sad or depressed. Everyone reacts differently to a chemical pregnancy, and there is no single, right response.

A Word From Verywell

If you are trying to conceive and are experiencing extreme anxiety (such as can happen in couples undergoing assisted reproduction), some doctors will advise against early pregnancy testing. It is important to remember that miscarriage from a chemical pregnancy is unavoidable. You can neither stop it nor intervene to prevent it.

In order to avoid extreme and unnecessary distress, do not test presumptively or in anticipation of a possible pregnancy, but rather wait until your period is actually late.

Sources:

Annan, J.; Gudi, A.; Bhide, P. et al. "Biochemical pregnancy during assisted conception: a little bit pregnant." Journal of Clinical Medical Research. 2013: 5(4):269-74; DOI 10.1042/jocmr1008w.

Doubilet, P.; Benson, C.; Bourne, T. et al. "Diagnostic criteria for nonviable pregnancy early in the first trimester." N Engl J Med. 2013; 369:1443-51; DOI 10.1056/NEJMra1302417.   

Larsen, C.; Christiansen, O.; Kolte, A. et al. "New insights into mechanisms behind miscarriage." BMC. 2013; 11:154; DOI 10.1186/1741-7015-11-154.

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