Clinical Significance

In general, increasing progesterone levels are indicative of viable pregnancies. Ultrasonography is required to confirm viability at low progesterone levels. Serum concentrations are relatively constant at 8-10 weeks gestation, unless the pregnancy is failing, which can be signaled by decreasing progesterone values. After 10-12 weeks, levels increase more rapidly, but serum progesterone determinations are not considered useful for diagnoses in late pregnancy.

Ovulation, and the presence of a functioning corpus luteum, can be demonstrated with serial determinations of serum progesterone. Luteal phase dysfunctions may be diagnosed when ovulation has occurred and there is inadequate luteinization and reduced progesterone secretion.

_{Source: Access Progesterone IFU #33550, 12/21/16}