There are many ways to confirm pregnancy - from folk methods to tests sold in each pharmacy. However, their reliability in the early stages is questionable, the exact answer is given by a blood test for the level of hCG - human chorionic gonadotropin, which is called the pregnancy hormone.
- Blood changes during pregnancy
- Human chorionic gonadotropin
- General blood test parameters
- When will
- Pregnancy test
Changes in blood during pregnancy
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The hCG hormone is produced by special cells of the chorion - the envelope of the embryo attached to thethe wall of the uterus. It consists of 2 units:
- alpha-hCG - has a similar structure with components of other hormones, for example, thyreotropic( TSH), follicle-stimulating( FSH), luteinizing( LH);
- beta-hCG - a unique unit, is crucial in diagnosis.
The levels of this hormone in the blood are important throughout the gestation period - they diagnose ectopic pregnancy and tumors, determine the multiplicity, and recognize the malformations of the fetus.
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General blood test parameters
Other changes in blood components are observed at later stages of pregnancy:
- Red blood cells - red blood cells, their number during pregnancy grows by 20-30%.Normal figures are above 3.5 billion in a liter of blood( 3.5 * 109 / L).
- Hematocrit is the volume of red blood cells in the liquid part of the blood, the index of increase in the plasma level. On average, the amount of plasma is increased by 50%, and of erythrocytes - only by a quarter, so the hematocrit decreases from 0.34-0.36 to 0.30-0.32( 30-32%).
- Hemoglobin is a protein in the composition of red blood cells, responsible for the transport of oxygen to tissues. In pregnant women, hemodilution develops when the blood is diluted with plasma, because of this the hemoglobin concentration also decreases and is 110-120 grams per 1 liter of blood.
- Leukocytes are white blood cells that protect the body from pathogenic agents. An increase in their level is considered a kind of norm and is often associated with a stressful( for pregnancy) hematopoiesis. The norm of leukocytes is up to 15 billion for 1 liter of blood( 15 * 109 / l).
- Platelets are blood components responsible for the early healing of damaged tissues. Their level during pregnancy can slightly decrease and amount to 100-400 billion in 1 liter of blood( 100-400 * 109 / L).
- Erythrocyte sedimentation rate( ESR) is a measure of blood separation in the capillary for plasma and red blood cells. Since there is a change in the qualitative composition of the blood proteins, this indicator increases to 30-40 millimeters per hour.
When
is shown, human chorionic gonadotropin is measured in milliunits per 1 milliliter of blood( mU / ml).Some laboratories measure this hormone in milli-international units per milliliter( mIU / ml) or nanograms per milliliter( ng / ml).
The ratio of these indicators is as follows:
- 1 mU / ml is 1 mIU / mL;
- 1 mU / ml is 21.28 ng / ml.
The blood test allows you to determine pregnancy in the early stages - already on day 6-8 after fertilization, the test for hCG will be positive. In non-pregnant women the level of this hormone does not exceed 5 million units in 1 milliliter of blood, in the first-second week of pregnancy this figure is 20-300 million units, in the second or third it can grow up to 4800 million units.
The work of test strips for determining pregnancy is also based on the study of the amount of hCG in the morning urine. However, the concentration of this hormone in the urine grows much more slowly, so a reliable test result is possible only at later terms - 2-3 weeks after conception.
Pregnancy analysis
Obtaining certain results will help compliance with certain rules:
- For the study, it is required to donate blood from the vein.
- Blood sampling is done in the morning, on an empty stomach, not less than 8 hours after the last meal.
- On the eve of testing should refrain from active physical exercises, exclude psycho-emotional stress.
- If the test is performed before the delay in menstruation, it is advisable to take blood 2 times with an interval of 2-3 days.
- The result may affect the intake of medications, in particular - hormonal drugs. They must always be warned by a doctor.
- It takes 1-2 days to process the analysis.