Urine pregnancy test operates on principle of detecting a particular hormone in urine, which exceeds 5mlU to indicate expectancy. The hormone is called human chorionic gonadotropin (HCG). The test is sensitive to above 20mIU of HCG in urine. The test can be done with a home test kit. When used correctly, home pregnancy tests are 97–99% accurate.

Urine pregnancy test operates on principle of detecting a particular hormone in urine, which exceeds 5mlU to indicate expectancy. The hormone is called human chorionic gonadotropin (HCG). The test is sensitive to above 20mIU of HCG in urine. The test can be done with a home test kit. When used correctly, home pregnancy tests are 97–99% accurate.

HCG is made in a woman’s placenta after a fertilized egg implants in the uterus. It is normally made only during pregnancy. The concentration of HCG in a non-pregnant woman is usually 5mIU. At the time after conception, the concentration rises to about 100mIU. The test is sensitive to 20mIU of HCG and is capable of detecting pregnancy as early as 7-10 days after conception. The test can be done with a home test kit. When used correctly, according to manufacture instruction, it gives an accuracy of about 97%.

ISAAC OGUTU ON EXPALINING THE TOPIC

BEST URINE SAMPLE

A urine specimen must be collected in a clean and dry container. It is better to take a urine sample first thing in the morning because it normally contains the highest levels of HCG of the day but samples can be used from any time of the day.

PROCEDURE

Open the sealed pouch and remove the strip. Place the test strip vertically (straight) into the urine sample, making sure the arrows are pointing down. Do not allow the urine surface to go above the maximum level line (marked by arrows) on the test strip. Leave the strip in the urine for at least 8 seconds (recommend 10 seconds). Remove the pregnancy test and place on a dry flat surface.

Wait for coloured bands to appear, depending on the concentration of HCG, results can be seen in as little as 40 seconds. However to confirm a negative result the complete reaction time (5 minutes) is required. Discard the test after use, put the used test in a special container and if possible regard it as infectious.

RESULTS

POSITIVE RESULT: If two coloured lines appear on the test strip,-That is both test and control lines, you are pregnant. One line may appear lighter than the other, but they will both be the same thickness. A faint line is more likely to occur when you are testing early and your hCG levels are low.

NEGATIVE RESULT: If only one coloured line- control line, appears on the test strip this is a negative result and you are either not pregnant or you may have tested too early. If you are unsure repeat the test in 48 hours with a new test strip.

INVALID RESULT: If no lines appear anywhere on the test strip or if only the test line appears, the test has not worked properly and is invalid. This is usually due to the strip not being wet enough. Repeat the test with a new test strip ensuring that the strip is immersed in the urine sample for the full 10 seconds.

RESULTS

CAUSES OF FALSE POSITIVE, FALSE NEGATIVE AND INVALID RESULTS

False Positive: Recent miscarriage, abortion, menopause, ovarian cysts in less than 3 months time, Outdated test kits, Contaminated test kits, rare medical conditions and taking fertility drugs

False Negative: Using over diluted urine, using a non-urine samples, Outdated and contaminated test kits, Testing too soon- less than 48hrs after conception

Invalid: Using wrong procedure, Inadequate sample-strip not wet.

BASELINE

ALWAYS follow manufacturer or expertise guideline in conducting the results. Do appropriate consultation if you are not sure of the results.

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