Is It a Miscarriage?

Progesterone test can predict miscarriage risk in pregnant women with bleeding

(RxWiki News) Pain or bleeding occurs early in pregnancy for about a third of all women. This may mean the baby won't survive, but not always. A simple test may help you know.

A recent study found that testing a women's levels of progesterone can often accurately predict whether a pregnancy will safely continue to term.

"Attend all prenatal visits."

The study, led by Jorine Verhaegen, a medical student in the Department of Obstetrics and Gynecology at Academic Medical Centre University in Amsterdam, Netherlands, aimed to figure out a way to test an unborn baby's likelihood of survival if the mother is experiencing pain or bleeding.

Currently, doctors generally use an ultrasound to try to figure out if a woman is likely to experience a miscarriage if she's having pain or bleeding during pregnancy.

Another way of testing the "viability" of a baby, or its likelihood of surviving, is to test the levels of progesterone in a woman's body.

Progesterone is a hormone whose levels increase during pregnancy.

The researchers reviewed 26 studies, including a total of 9,436 pregnant women who had their progesterone levels tested when they were experiencing pain or bleeding.

In seven of these studies, the women experiencing pain or bleeding received an ultrasound whose results were inconclusive regarding her baby's viability.

In the other 19 studies, the women had only pain or bleeding but were not given an ultrasound.

The researchers analyzed the quality of each study so they they could take this into account and compare the results as adequately as possible.

The researchers found that, most of the time, if a woman's progesterone levels are low, it's unlikely that the pregnancy will be able to be carried to full term.

However, the analysis of the studies revealed that the accuracy of testing a pregnancy's likelihood of going to term with progesterone levels was more accurate if the women first had an inconclusive ultrasound.

"The outcome of a pregnancy in women with pain or bleeding in early pregnancy cannot be determined clinically alone after inconclusive ultrasound assessment," the authors wrote. They said that about a quarter of the time, the pregnancy may simply be too early on for the baby to show up on the ultrasound.

The authors also offered caution about relying completely on a progesterone test to determine a pregnancy's viability because some pregnancies may occur with low progesterone levels but still produce a healthy baby.

It is when the low progesterone is paired with an inconclusive ultrasound and pain and/or bleeding that it is most likely a pregnancy that will not survive.

"In conclusion, this meta-analysis found that a single progesterone measurement for women in early pregnancy presenting with bleeding or pain and inconclusive ultrasound assessments can rule out a viable pregnancy," they wrote.

Jennifer Mushtaler, MD, an OBGYN at Capital Ob/Gyn Associates of Texas, pointed out that even the combination of the ultrasound and hormone levels testing is not 100 percent reliable.

"Diagnosing miscarriage can be tricky in the early stages of pregnancy when it is not easily visualized on ultrasound," she said. "Serial measurements of beta HCG, a pregnancy hormone, as well as a progesterone level are very helpful but by no means absolute."

Dr. Mushtaler said that the best option is often to wait and see.

"Ultimately, waiting just a few weeks can clarify if a pregnancy is viable or if it results in miscarriage," she said. "During that time, patients should get extra rest and call their doctor if bleeding heavier than a period is experienced."

The study was published September 27 in the journal BMJ. The study did not receive outside funding, and the authors declared no conflicts of interest.

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Review Date: 
October 8, 2012