Hcg Lab Report

MLAB 320 – Clinical Chemistry III hCG Question: What is it? Answer: Human Chorionic Gonadotrophin (Molecular weight = 45,000) Pronounced Human KOREEONIK GO-NAD-O-TRO-FIN It is a glycoprotein secreted by the syncytiotrophoblastic cells of the normal placenta. It consists of two subunits and . These subunits are not similar. The subunit is common to three other hormones… • LH • FSH • TSH hCG

Luteinizing Hormone. Follicle Stimulating Hormone. Thyroid Stimulating Hormone

The

subunit is unique to

The detection of urinary HCG is widely as a sensitive test for the early recognition of pregnancy.

Introduction. Pregnancy usually begins in the middle of the Fallopian tubes when fertilization occurs. Sperm penetrates the ovum (female egg). The sperm’s tail breaks off and the nuclei of both the sperm and the ovum, fuse. A genotype cell of 46 chromosomes is formed. The cell divides to form a BLASTOCYST. This BLASTOCYST moves towards the uterus by ciliary movement and peristalsis of the Fallopian tubes. Outer layers of cells are formed and they are called the TROPHOBLAST. (fig 1) The TROPHOBLAST layer of cells is made up of two layers of cells. The inner layer is called the CYTOTROPHOBLAST and the outer layer is called the SYNCYTIOTROPHOBLAST. i.e. 1. CYTOTROPHOBLAST (inner layer of cells) 2. SYNCYTIOTROPHOBLAST (outer layer of cells)

TROPHOBLAST

Syncytiotrophobla

O

Sperm

Foetal Cytotrophoblas

1

MLAB 320 – Clinical Chemistry III Fig 1. About seven days after the fertilization of the ovum, the blastocyst implants in the uterus. It does this by secreting enzymes from the syncytiotrophoblastic cells, which erode on the wall of the uterus. This allows implantation of the Foetal Embryo. The syncytiotrophoblast also produces other placental hormones including….. • Progesterone. • Oestriol • Human Placental Lactogen (HPL) • B HCG

Function of HCG HCG has an important role in maintaining the function of the of the ovum until the placenta starts producing it’s own progesterone. Clinical Applications of hCG. Measurement of hCG in bodily fluids such as sera and urine may be used for a number of reasons…… 1. To diagnose early pregnancy. 2. To monitor a normal pregnancy. 3. To help diagnose and monitor ectopic pregnancy or possible abortions. 4. To help diagnose and monitor trophoblastic disease.

HCG in a normal pregnancy. Detectable amounts of hCG of approximately 5IU/L are present 8 - 11 days after conception (fertilization) . HCG reaches it’s peak between 8 - 10 weeks from the last menstrual period (LMP) and reaches a level of about 100,000 IU/L in the serum of a pregnant woman. HCG then starts to decline and by the end of the 2nd Trimester a 90% reduction has occurred. Levels are now low but constant during the 3rd Trimester. LMP

Deliver

Fertilizatio Implantation of ovum in hCG

HPL Oestriol

Progesterone

2

MLAB 320 – Clinical Chemistry III 0 14 21 70 180 260 Days st nd rd 1 Trimester 2 Trimester 3 Trimester There are three common problems affecting the prostate gland. These may be listed as:

Answer the following questions: 1. How high are the levels of hCG in women who are pregnant with twins compared to a single pregnancy? 2. What is the principle of the test? 3. What are the reagents in the kit? 4. How should the kit be stored? 5. What kind of sample is needed? 6. Follow the procedure in the handout. What is the time limit for reading the test? 7. Use the standard values and absorbances to draw a curve. Read your controls and patient values from your curve. 8. Each group of 2 students will discuss one of the following: a. Twin to twin transfusion syndrome b. How do identical twins develop? How do non-identical twins develop? c. How do conjoined twins develop?

3