Progesterone

This test is used to establish the presence of a functioning corpus luteum or luteal cell function; confirm basal body temperature measurements for the occurrence of ovulation; obtain an indication of the day of ovulation; evaluate the functional state of the corpus luteum in infertility patients; assess placental function during pregnancy; and as an ovarian function test.

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or who have received them for diagnostic purposes.¹ In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.¹ The test contains additives that minimize these effects.

Electrochemiluminescence immunoassay (ECLIA)

This assay is performed on the Roche cobas instrument in multiple laboratories throughout Labcorp.

Progesterone is a steroid hormone with a molecular weight of 314.5 daltons.² Progesterone is mainly formed in the cells of the corpus luteum and during pregnancy in the placenta. Progesterone is increased in congenital adrenal hyperplasia due to 21-hydroxylase, 17-hydroxylase, and 11-β-hydroxylase deficiency. Progesterone is decreased in primary or secondary hypogonadism and short luteal phase syndrome.

The progesterone concentration correlates with the development and regression of the corpus luteum. Whereas progesterone is barely detectable in the follicular phase of the female cycle, a rise in the progesterone level is observed one day prior to ovulation. Increased progesterone synthesis occurs during the luteal phase. In the second half of the cycle pregnanediol is excreted in urine as the main degradation product of progesterone.

Progesterone brings about the conversion of the uterine mucosa into a tissue rich in glands (secretion phase), in order to prepare for the intrauterine implantation of the fertilized ovum. During pregnancy, progesterone inhibits the contraction of the myometrium. In the mammary gland, progesterone (together with estrogens) promotes the proliferation and secretion disposition of the alveoli.^2,3

The determination of progesterone is utilized in fertility diagnosis for the detection of ovulation and assessment of the luteal phase.^3,4