Progesterone Assay
Sample
- This is done on the serum of the patient.
- Always note the sex of the patient.
- In the female note the day of the last menstrual cycle.
- The serum is stable for 7 days at 4 °C.
- Can store serum for 3 months at -20 °C.
Precautions
- Avoid hemolysed samples that will affect the result.
- Take history recent use of radioisotopes because that will affect the result.
- Estrogen and progesterone therapy will interfere with the result.
Indication
- This test is part of the infertility study.
- Confirm ovulation.
- To evaluate the corpus luteum function.
- To assess high risk for early spontaneous abortion.
Pathophysiology
- Progesterone is a female sex hormone needed to prepare the uterus for pregnancy.
- progesterone is C21 steroids.
- The initiation and control of luteal secretion of progesterone are regulated by LH and FSH.
- Progesterone has no specific binding plasma protein. This is bound like cortisol to cortisol binding globulin.
- Free progesterone is 2 to 10% of the total concentration and this will remain constant throughout the menstrual cycle.
- This is like estrogen as a sex hormone.
- It helps to regulate the accessory organs during the menstrual cycle.
- Progesterone acts primarily on the endometrium.
- It starts the secretory phase of the endometrium for the preparation for the implantation of a fertilized ovum.
- This is important for the implantation of the blastula that is produced by the cleavage of the fertilized ovum.
- In nonpregnant females, it is produced by the corpus luteum.
- Progesterone maintains the pregnancy.
- Source of progesterone production:
- Progesterone is produced by the Corpus luteum (granulosa cells) of the ovary in the first week of pregnancy.
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- The adrenal cortex and testes are a minor source of progesterone in the male.
- The adrenal cortex is a minor source of progesterone in the female as well.
- Followed by Placenta during pregnancy which starts producing progesterone.
- Placenta produces progesterone by 12 weeks of gestation.
- The adrenal cortex and testes are a minor source of progesterone in the male.
- The progesterone peak level is a mid-luteal phase of the menstruation.
- In non-pregnant women, progesterone is produced by the corpus luteum.
- Progesterone in nonpregnant ladies is elevated during the luteal phase, maximal level 5 to 10 days after the LH peak at mid-cycle.
- Progesterone is metabolized into the metabolites which conjugate with glucuronic acid and excreted as water-soluble glucuronides.
- The single best test to evaluate ovulation.
- A series of the test gives the day of ovulation when there is the peak level of progesterone.
- Plasma progesterone level starts to rise with ovulation along with LH hormone approximately 6 to 9 days.
- The level falls and menses occur.
- After ovulation, there is a rise of 4 to 5 days and then it falls.
- In case of inadequate luteal phase production of progesterone, supplementary progesterone can be given to maintaining early pregnancy.
- In pregnancy, there is a gradual increase starting from the 9 weeks to 32 weeks of gestation.
- Its level is higher in the twin pregnancy.
- Progesterone is converted into Pregnanediol and conjugated with glucuronic acid by the liver and then excreted by the kidneys.
- Progesterone 2 to 10% free and rest is bound to corticosteroid-binding globulin (CBG).
- Pregnanediol is most easily measured by a metabolite of the progesterone in the urine and plasma.
- Pregnanediol level in the urine is unchanged even in the fetal distress or even the death of the fetus.
- Progesterone and Estradiol (most potent of the estrogen), their role in the secretion of FSH and LH.
NORMAL
Source 1
Age | ng/dL | |
Cord blood | 8000 to 56,000 | |
Premature | 84 to 1360 | |
Prepubertal child (1 to 10 years) | 7 to 52 | |
Puberty Tanner stage | Male | Female |
1 | <10.3 to 33 | <10 to 33 |
2 | <10 to 33 | <10 to 55 |
3 | <10 to 48 | <10 to 450 |
4 | <10 to 108 | <10 to 1300 |
5 | 21 to 82 | 10 to 950 |
Adult | 13 to 97 | Follicular phase = 15 to 70 |
Luteal = 200 to 2500 | ||
Pregnancy | ||
First trimester = 1025 to 4400 | ||
2nd trimester = 1950 to 8250 | ||
3rd trimester = 6500 to 22,900 |
- To convert into SI unit x 0.0318 = nmol/L
- Tanner stage is the physical scale of development of primary and secondary sex characteristics.
Source 2
- Adult male = 10 to 50 ng/dL
- Adult female:
- Follicular phase = <50 ng/dL
- Luteal phase = 300 to 2500 ng/dL
- Postmenopausal = <40 ng/dL
- In Pregnancy:
- First trimester = 725 to 4400 ng/dL
- Second trimester = 1950 to 8250 ng/dL
- Third trimester = 6500 to 22,900 ng/dL
Source 4
- Men = < 1.0 ng/mL.
- Women
- Prepubertal = 0.1 to 0.3 ng/mL.
- Follicular phase = 0.1 to 0.7 ng/mL.
- Luteal phase = 2 to 25 ng/mL.
- Pregnancy:
- First trimester = 10 to 44 ng/mL.
- Second trimester = 19.5 to 82.5 ng/mL.
- Third trimester = 65 to 290 ng/mL.
- There is a lab to lab and method to method variation of the normal values.
Increased progesterone level is seen in:
- Congenital adrenal hyperplasia.
- Molar pregnancy.
- Lipid ovarian tumor.
- At the time of ovulation.
- Pregnancy.
- Choriocarcinoma of the ovary.
- Theca Lutein cyst of the ovary.
Decreased level of progesterone seen in:
- Threatened spontaneous abortion.
- Preeclampsia.
- Toxemia of pregnancy.
- Fetal death.
- Placental failure.
- Ovarian hypofunction.
- Amenorrhea.
- Ovarian cancers.
- Short luteal phase syndrome.