Serum progesterone

What is Serum Progesterone?

Serum progesterone is a steroid hormone produced by the corpus luteum and the placenta. It has many roles in the female body, especially during pregnancy. Its levels fluctuate throughout the menstrual cycle.

Preparation and Procedure

It is usually done as part of a fertility workup, a check for menopause or a checkup to make sure the woman is not pregnant. During the procedure, the woman's blood is taken and sent off to the lab to measure serum progesterone levels.

Types of Serum Progesterone

There are two types of serum progesterone: free and bound. Free progesterone is the active form. Free progesterone is the form that binds to progesterone receptors in target tissues. The bound type of serum progesterone includes proteins that act as carriers, inactivating it.

Risks of Serum Progesterone Test

Serum progesterone tests do not have any risks associated with them, except the normal risks of getting your blood drawn.

When to Test Serum Progesterone Levels

It is typically tested on day 21 of the menstrual cycle to make sure there is enough for the egg to implant in the uterus. It is also useful for women who are having fertility treatments or IVF.

Why Test Serum Progesterone Levels?

Serum progesterone tests can help diagnose any underlying health issues, identify the cause of infertility, or even help detect premature labor. Measuring this progesterone level is useful to help diagnose and follow treatment in women who have irregular or abnormal menstrual cycles or unexplained bleeding.

Normal Serum Progesterone Levels

  • Follicular phase: 0.25-1.5 ng/ml
  • Ovulation phase: 5-25 ng/ml
  • Luteal phase: 10-25 ng/ml
  • Early pregnancy: 10-200 ng/ml
  • Advanced pregnancy: 100-1,000 ng/ml