Progesterone

Sample for Progesterone

1. This is done on the serum of the patient.
2. Always note the sex of the patient.
3. In the female, note the day of the last menstrual cycle.
4. The serum is stable for 7 days at 4 °C.
5. Can store serum for 3 months at -20 °C.

Precautions for Progesterone assay

1. Avoid hemolysed samples that will affect the result.
2. Take the history of the recent use of radioisotopes because that will affect the result.
3. Estrogen and progesterone therapy will interfere with the result.

Indication for Progesterone assay

1. This test is part of the infertility study.
   1. Confirm ovulation.
   2. To evaluate the corpus luteum function.
2. To assess the high risk for early spontaneous abortion.

Definition of progesterone

1. Progesterone is a sex hormone like estrogen.
2. It helps to regulate the accessory organs during the menstrual cycle.
3. Progesterone is an important hormone for preparing the uterus for the reception of the blastocyst and maintaining the pregnancy.

Pathophysiology of Progesterone

1. Progesterone is a female sex hormone needed to prepare the uterus for pregnancy.
2. progesterone is C_²¹  steroids.
3. The initiation and control of luteal secretion of progesterone are regulated by LH and FSH.
4. Progesterone has no specific binding plasma protein. This is bound like cortisol to cortisol binding globulin.
5. Free progesterone is 2% to 10% of the total.
6. This is like estrogen as a sex hormone.
7. It helps to regulate the accessory organs during the menstrual cycle.
8. Progesterone acts primarily on the endometrium.
9. It starts the secretory phase of the endometrium for the preparation for the implantation of a fertilized ovum.
10. This is important for the implantation of the blastula that is produced by the cleavage of the fertilized ovum.
11. In nonpregnant females, it is produced by the corpus luteum.
12. Progesterone maintains the pregnancy.

Structure of the progesterone:

1. Progesterone is a C21 compound.
2. Like corticosteroids and testosterone, it contains a keto group at C3 and a double bond between C4 and C5.

Source of progesterone production:

1. Progesterone is produced by the Corpus luteum (granulosa cells) of the ovary in the first week of pregnancy.

2. In non-pregnant women, progesterone is secreted mainly by the corpus luteum.
3. During pregnancy, the placenta is the main source of progesterone production.
   2. Placenta produces progesterone by 12 weeks of gestation.
   3. Followed by Placenta during pregnancy which starts producing progesterone.
4. The adrenal cortex and testes are minor sources of male progesterone production.
   1. The adrenal cortex is also a minor source of progesterone in the female.
5. Progesterone is metabolized into metabolites conjugated with glucuronic acid and excreted as water-soluble glucuronides.

Transport of the progesterone:

1. Progesterone has no specific plasma-binding proteins.
2. Progesterone is bound to corticosteroid-binding globulin
3. Plasma-free progesterone varies from 2% to 10% of the total concentration. This unbound progesterone remains constant throughout the normal menstrual cycle.

Progesterone level in the body:

1. The progesterone peak level is a mid-luteal phase of menstruation.
   1. In non-pregnant women, progesterone is produced by the corpus luteum.
   2. Progesterone in nonpregnant ladies is elevated during the luteal phase, with maximal level 5 to 10 days after the LH peak at mid-cycle.

The single best test to evaluate ovulation:

1. A series of the test gives the day of ovulation when there is a peak level of progesterone.
2. Plasma progesterone level starts to rise with ovulation along with LH hormone approximately 6 to 9 days.
3. The level falls, and menses occur.
4. After ovulation, there is a rise of 4 to 5 days, and then it falls.
5. Supplementary progesterone can be given to maintain early pregnancy in case of inadequate luteal phase production of progesterone.
6. There is a gradual increase in pregnancy from 9 weeks to 32 weeks of gestation.
7. Its level is higher in the twin pregnancy.

Progesterone metabolites:

1. Progesterone is converted into Pregnanediol, conjugated with glucuronic acid produced by the liver, and then excreted by the kidneys.
   1. Progesterone 2% to 10% free and rest is bound to corticosteroid-binding globulin (CBG).
2. Pregnanediol is most easily measured as a metabolite of progesterone in the urine and plasma.
   1. Pregnanediol level in the urine is unchanged even in fetal distress or even the death of the fetus.

3. Progesterone and Estradiol, their role in the secretion/inhibition of FSH and LH.