Positive Pregnancy Test After a Miscarriage

You May Be Pregnant Again or Experiencing an Incomplete Miscarriage

Scared woman looking at pregnancy test
Bambu Productions/Getty Images

If you've had a diagnosis of miscarriage, you may be confused if you take a pregnancy test and find that it's positive.

What does this mean? This is actually a common source of confusion with a few different explanations.

How a Pregnancy Test Works

In order to understand why you may have a positive pregnancy test even after a miscarriage, it's helpful to understand how a pregnancy test works.

Pregnancy tests detect the presence of the pregnancy hormone hCG (human chorionic gonadotropin) in the blood or urine.

Most of the time hCG is only in a woman's body during pregnancy, so a test is usually fairly conclusive for pregnancy. (There are some rare ovarian tumors which secrete hCG, but these are extremely uncommon.)

However, after an embryo or fetus stops growing and a miscarriage occurs, the hormone does not disappear from a woman's body right away. The level of hCG gradually decreases, falling back down to zero over a period of days, or even weeks, depending on how far along the pregnancy was when the miscarriage happened.

Because today's pregnancy tests usually detect even very low levels of hCG, taking a pregnancy test in the days or immediate weeks after your miscarriage can still show a positive result. You may also continue to feel pregnancy symptoms after a miscarriage, even when it is 100 percent certain that you have miscarried.

Time Frame for hCG to Return to Normal

All in all, it takes an average of 12 to 16 days for hCG to disappear from the body, but this can vary based on how high your hCG level was at the time of your miscarriage.

 It can take around a week to return to zero with a chemical pregnancy (a very early pregnancy loss) and up to a month, or even more, with a miscarriage that occurs later in pregnancy. After that, a pregnancy test won't be detected as positive.

Causes of a Persistent Positive Pregnancy Test After Miscarriage

Most of the time, your hCG level will return to zero in the time noted above.

But what if you continue to have a positive pregnancy test and/or continue to have pregnancy symptoms?

If it has been more than a couple of weeks since your miscarriage, you should call your doctor if you are still getting a positive pregnancy test. In this situation, your doctor may want to monitor your hCG level with blood tests (a quantitative hCG.) If you continue to have a positive blood pregnancy test, there is a possibility that you are:

  • Pregnant again
  • Experiencing an incomplete miscarriage
  • Experiencing a molar pregnancy (very rare)

Pregnant Again

If you have been sexually active and have a positive pregnancy test soon after a miscarriage, it's also possible that you might be pregnant again. Your doctor will be able to tell you for sure one way or the other, though she may need to follow you with blood hCG tests to know for sure.

Although many women are not aware of this, it's possible to become pregnant during your first menstrual cycle after a miscarriage. If you are not trying to become pregnant after your pregnancy loss, you should use contraception to prevent a pregnancy until you are ready.

Incomplete Miscarriage

With an incomplete miscarriage, there is still pregnancy tissue leftover in your uterus.

Unfortunately, it does not mean that your pregnancy is continuing or is viable.

You may need a simple surgical procedure called a D&C (dilation and curettage) to remove the retained products of conception, which is usually only small pieces of the placenta. These tissues will probably be reabsorbed (broken down) by your body in time, but surgery can help put a stop to heavy bleeding sooner, as bleeding is a common symptom of an incomplete miscarriage.

Molar Pregnancy

Very rarely, a positive pregnancy test may occur with gestational trophoblastic disease— a term used to describe several conditions (like a molar pregnancy) in which there is an abnormal growth of placental tissue.

When Can I Get Pregnant After a Miscarriage?

Talking about getting pregnant can be painful after you've had a miscarriage. It's important, however, for those who would like to become pregnant again, to be aware of the myths. In the past, it was thought that getting pregnant within six months of a miscarriage raised the risk of complications ranging from toxemia to stillbirth, and in fact, doctors often recommended that women wait. These concerns are simply not true.

Research now suggests that there is no increased risk of problems if women become pregnant shortly after a miscarriage.

A Word From Verywell

Experiencing a miscarriage can be an emotional rollercoaster and the confusion over a persistently positive pregnancy test can add to this already difficult situation. Be assured that it can take a variable amount of time (on average two weeks) for a woman's hCG level to disappear after a miscarriage.

Still, if you feel like something is not right, or you are experiencing heavy or persistent bleeding, worsening pelvic pain, or a fever with your miscarriage, seek medical guidance. 

Sources:

Kangatharan C, Labram S, Bhattacharya S. Interpregnancy Interval Following Miscarriage and Adverse Pregnancy Outcomes: Systematic Review and Meta-Analysis. Human Reproduction Updat231.

Love E, Bhattacharya S, Smith N, and Bhattacharya S. Effect of Interpregnancy Interval on Outcomes of Pregnancy After Miscarriage: Retrospective Analysis of Hospital Episode Statistics in Scotland. BMJ. 2010. 341:c3967.

Shaaban A et al. Gestational Trophoblastic Disease: Clinical and Imaging Features. Radiographics. 2017 Mar-Apr;37(2):681-700.

Continue Reading