For pregnant women in Pittsburgh, few things are scarier than prenatal problems. Perhaps even more terrifying is not knowing with certainty how to interpret every symptom pregnant women have. Bleeding, for example, can mean that a woman has had a miscarriage. However, vaginal bleeding is not always indicative of fatal problems.

To determine whether a miscarriage has occurred, doctors use guidelines to measure a variety of factors. But a frightening new study revealed that those guidelines are not as accurate as they should be, and human error is to blame for fatal birth injuries.

In short, doctors terminate perfectly healthy pregnancies believing the pregnancy has already ended.

An article in The Atlantic explained the medical procedure in this way, “Doctors use ultrasound to measure the gestational sac and the embryo at one time point, and then follow up with a second measurement one week to 10 days later to see whether growth has occurred.”

That method of measurement leaves too much room for error.

First, there are new studies that are examining how much fetuses change during the early weeks of pregnancy. Although there are expected growth rates during every stage of pregnancy, it is possible for a healthy fetus to show no growth between two measurement points.

Second, doctors’ measurements can vary by up to 20 percent for any one fetus at a single point in time. As a result, if the first doctor over-measured the size of a fetus and the second doctor under-measured the size of the fetus, a doctor could wrongly conclude that the fetus had not grown.

If a doctor determines that there has not been any growth in the fetus, he or she might conclude that the woman had a miscarriage. The co-author of the study stated that “there is a risk that some women seeking reassurance with pain or bleeding in early pregnancy may be told they have had a miscarriage, and choose to undergo surgical or medical treatment when the pregnancy is in fact healthy.”

Sadly, there is very little that most women can do to prevent miscarriages. However, doctors can help by ensuring they are not misdiagnosing healthy pregnancies, thereby causing women to abort healthy babies.

Source: The Atlantic, “A False Positive for Miscarriage: Terminating Healthy Pregnancies,” Alice G. Walton, Oct. 21, 2011