In evaluating early pregnancy, a single progesterone measurement can rule out viability, depending on the cutoff levels used and whether ultrasound is available, according to a BMJ meta-analysis.

Researchers examined data from 26 cohort studies including some 9500 pregnant women, some with symptoms and inconclusive ultrasound results, and others with only symptoms.

In studies with inconclusive ultrasound results, a progesterone cutoff level between 3.2 and 6 ng/mL gave a sensitivity of 75% and a specificity of 98% for predicting a nonviable pregnancy.

In studies with symptoms alone, a progesterone cutoff of 10 ng/mL gave a sensitivity of 67% and a specificity of 96%.

The authors conclude that the test “is more accurate when it follows an inconclusive ultrasound.”

Source: BMJ