ugg
Client SurveyCape Town
     
 
 
   Pregnancy frequently asked Questions and Answers      
               
  How does a rapid diagnostic pregnancy test detect pregnancy?  
 
 
     
  Rapid diagnostic pregnancy tests detect the presence of the hormone hCG (human Chorionic Gonadotropin) in a woman's urine. hCG is a
glycoprotein hormone secreted by the developing placenta shortly after fertilization. Once the egg implants in the uterine lining, hCG is produced
and secreted by the placenta. hCG can be detected in blood and urine samples.		  
               
  Urine pregnancy tests detect hCG and will indicate a positive result when the hCG level in a sample reaches a specific threshold. If the amount of hCG in the urine sample is sufficient to exceed the threshold - or sensitivity level - a "test line"  
               
  will appear indicating a positive result.  If the hCG level in the urine sample is below this sensitivity level, no test line will appear, indicating either a negative result for pregnancy or that the level of hCG is still below the detection limit of 20 mIU/ml.  
     
  Should you suspect pregnancy, repeat the test 48 hours later.  
               
  Does the hCG sensitivity of the pregnancy test matter?    
 
       
               
  The sensitivity of a pregnancy test determines how soon after conception pregnancy can be detected by the test. Concentrations of hCG
(human Chorionic Gonadotropin) are reported in milli International Units per ml, or mIU/ml. Pregnancy tests with a sensitivity of 20 mIU/ml are more sensitive than tests with a sensitivity of 50 to 100 mIU/ml.		  
               
  High sensitivity, 20 mIU/ml, tests, such as U-Test Pregnancy equates to early detection of pregnancy. This means that you can begin testing
accurately as early as eight days after conception or 2-3 days before expected menstruation. Conception may take place several days after
 date of intercourse, so the date of intercourse should not be viewed as the day of conception.		  
               
  How accurate are rapid diagnostic pregnancy tests?      
 
       
           
  Rapid diagnostic pregnancy tests are very accurate. Inaccuracies are most often traced to errors in doing the test or failure to follow instructions with care. There are circumstances and variables that may influence pregnancy test result (from fertility medications to diluted urine sample or testing too early for pregnancy).  
               
  All pregnancy tests are not the same!  
               
  Read the instructions! One common mistake many people make is generalizing the procedure of one test to another. Incorrect or “failed” pregnancy tests can often be attributed to misinterpretation of results or to a failure to follow test instructions.  
               
  Why you should use first morning urine or hold urination      
 
       
               
  Rapid diagnostic pregnancy tests detect hCG and therefore it is best to use urine samples containing the highest amount of the hCG hormone. Diluted urine samples (from drinking high volumes of water / frequent urination) will reduce the level of hCG and therefore influence the test accuracy.  
     
  First morning urine is considered the ideal sample as it contains the highest concentration of hCG (human Chorionic Gonadotropin) - given that
 you have not urinated frequently throughout the night.		  
     
  If a pregnancy test is done later in the day, make sure that you do not urinate 3 to 4 hours before testing.  
     
  Doing an early pregnancy test: how soon can you test for pregnancy?    
 
   
               
  hCG pregnancy tests determine pregnancy through the detection of the hormone hCG (human Chorionic Gonadotropin) in a woman's urine.
In technical terms, hCG is a glycoprotein hormone secreted by the developing placenta shortly after a fertilized egg has implanted in the uterine
lining. Clinically speaking, hCG is measured in thousandths of International Units, or mIU/ml. Pregnancy tests with a sensitivity of 20 mIU/ml are
 more sensitive than tests with a sensitivity of 50 to 100 mIU/ml.		  
     
  In pregnancy, hCG levels vary from person to person and at different rates. Implantation normally occur 6-8 days post conception followed by
 a very low level of hCG. The levels of hCG increases to about 30 mIU/ml after 10 days following fertilization. During the first missed period,
the level is generally between 50 -250 mIU/ml.		  
     
  Pregnancy test brands will display how sensitive their tests are using mIU/ml as the standard unit of measure. Test sensitivity equates with early-detection - and the lower the mIU/ml value, the earlier a test can detect pregnancy. The most sensitive pregnancy tests can detect hCG levels
at as low as 20 mIU - or at around 8 days following implantation of the egg or up to two days before expected menstruation.		  
     
  When a woman is pregnant, her level of hCG should be around 25 mIU at 10 dpo (days past ovulation), 50 mIU at 12 dpo, 100 mIU at around
two weeks dpo. Blood tests can determine pregnancy at levels as low as 5 to 10 mIU/hCG, however with levels of 5 mIU, a conclusive
determination cannot be made without risking a "false positive" as low levels hCG can be present in the body without pregnancy. For earliest
 detection of pregnancy, use first morning urine, as this sample contains the most concentrated amount of hCG. If using first morning urine is
not possible, avoid urinating several hours before using a pregnancy test. Frequent urination - or a diluted sample - will decrease the level of
hCG in your urine and may give a false native test result.		  
     
  What does a faint line on a pregnancy test mean?    
 
       
               
  On a pregnancy test, a faint test line - or colour band (in comparison to the control band) - indicates a positive result, as long as it is read within
the allocated time frame - or reaction time of the test (15 minutes). If you do the pregnancy test properly and read it within the recommended time frame, then a faint and weak line is very likely a positive pregnancy test.		  
               
  The presence of hCG (human chorionic gonadotropin) doubles every two days in a pregnant woman. In cases where a faint test colour
 band is present, it is recommended that another test is done after 24 - 48 hours using first morning urine.		  
               
  Explanations for a faint positive line include      
 
  • You may be testing too early after conception - your hCG level may be below the detection level of test. hCG doubles every two days,
    so wait and test again after 24 -48 hours using first morning urine.
  • Different test sensitivity - as tests detect hCG at different levels, a faint line on one test brand may appear as a darker line on for example
    a 20 mIU test like U-Test.
  • Urine dilution – the urine may be diluted due to frequent urination or a high consumption of liquids. First morning urine is recommended for pregnancy testing as it contains the highest concentration of hCG.
  • Chemical pregnancy - sometimes, an early pregnancy is detected - followed by negative test results. A chemical pregnancy occurs when
  • a fertilized egg does not implant into the uterine wall. The menstrual cycle usually begins on time or a few days late.
  
 

Back To Top    

 
  What are the causes of a "false positive" result on a rapid diagnostic pregnancy test?    
 
       
               
  False positive tests are rare - though there are instances and conditions where they can occur. For example, research indicates that 50 – 60% of
all conceptions (fertilized eggs) do not develop into pregnancy. This is termed chemical pregnancy. A chemical pregnancy occurs when a fertilized
egg does not implant into the uterine wall, it produces hCG but does not develop into normal pregnancy. It is a term used to describe a very early miscarriage		  
     
  Most "false positive" pregnancy tests can be attributed to misinterpretation of results due to a failure to follow test instructions with precision. You should not rely on any positive result that does not show up within the time limit stated on the test instructions.  
     
  Expired test or improperly stored pregnancy test - make sure to check the expiration date on your pregnancy test as well as the storage instructions. An expired test or improperly stored pregnancy test may not work accurately.  
     
  An evaporation line is caused by urine evaporating from a pregnancy test. The line results in the area where a positive result would normally be
 seen. Evaporation lines generally do not have any colour to them. They look more like a shadow.		  
     
  Reading tests results after manufacturer's recommended time. A faint positive test result may occur if you read the pregnancy test after the manufacturer's recommended time. Some pregnancy tests will continue to react to urine and produce a false positive result if read after
 recommended time period.		  
     
  Some medications that contains hCG that will interfere with the test result.  
               
  Do not try to interpret the tests before or after the allotted test reaction time      
 
     
               
  Results should not be read before or after the allotted test reaction time - 15 minutes. Yes, the temptation is there to keep reading the test until it
gives you the result you want, but remember: rapid diagnostic tests are diagnostic products designed to be used within strict clinical guidelines.
 For best results, follow the instructions carefully and methodically as if YOU were a doctor in a clinic.		  
               
  What if the test is negative after the 15 minute reaction time, but becomes positive after an hour or more?  
 
 
               
  Do not attempt to interpret results after the test reaction time specified by the manufacturer. You should not rely on any positive result that does
 not show up within the time limit stated on the test instructions.		  
               
  Can I be pregnant when I get a false negative result?      
 
       
        Back To Top    
  False negative results are more common than false positives.  
 
  • A false negative result can stem from using a diluted urine sample and/or from taking a test too early in pregnancy. First morning urine
    contains the most concentrated presence of hCG (human Chorionic Gonadotropin) - which makes it the ideal sample for pregnancy testing.
  • Additionally, at the same gestational stages, women produce quantitatively different levels of hCG - which means that the first indication
    of a positive result on a rapid diagnostic pregnancy test may vary between women, despite a similar gestational stage. Should the test
    indicate a negative result after menstruation should have started, test again after 48 hours as the hCG doubles +- every 24 hours. This additional time will allow your hCG levels to increase to a detectable level. If you suspect you that you are pregnant, you should see your doctor for a blood hCG test, no matter what result you get from any rapid diagnostic pregnancy test.
  • If the rapid diagnostic pregnancy test was stored incorrectly e.g. exposed to direct sunlight or frozen, the reagent used to develop the
    test result will be damaged and rendered ineffective and may give a negative test result. Tests results are also influenced by humidity.
    • Rapid diagnostic pregnancy tests should be stored at room temperature (4°- 30°C). The test should be kept from direct sunlight, moisture and heat. Do not freeze! If the rapid diagnostic pregnancy test was stored incorrectly e.g. exposed to direct sunlight or frozen, the reagent used to develop the test result will be damaged and rendered ineffective and may give a negative test result.
    • All rapid diagnostic screening tests should be protected from humidity at all times. Rapid diagnostic pregnancy tests are packed
      in a foil sleeve to keep the test dry and protect it from humidity. If the test is removed from this protective packaging and left open (especially at the coast), it will render the test ineffective.
  
  In winter when room temperatures are cold or low, rapid diagnostic pregnancy tests will take longer to develop a test result. All rapid diagnostic screening tests should be done at temperatures above 15°C.  
               
  For very low concentrations of hCG in a urine sample e.g. early pregnancy or diluted urine, the reaction time can take up to 15 minutes to develop.  
               
  Can fertility drugs or medication interfere with pregnancy test results?      
 
       
               
  If patients are taking fertility medications, consult with the doctor to make sure that they do not interfere with pregnancy testing results.
Medications that can cause a false positive on a pregnancy test are medication that contain hCG itself e.g. Novarel, Profasi, Pregnyl.
Other fertility drugs and medications that do not contain hCG will not precipitate false positive results. Similarly, progesterone will not cause
 a false positive as well.		  
               
  Urine aim, drop or dip with precision for the best results with a rapid diagnostic pregnancy test      
 
 
               
  On midstream tests, if a woman urinates directly into the test window, or if test strip users dip the entire test strip into the urine, these
 procedural errors will invalidate test results and both the control and test bands will probably not appear at all. Rapid diagnostic screening
 tests function by urine flowing from the bottom of the test via an absorbent medium to pass through anti-hCG antibodies and onto an
 accompanying colour dye for a reaction to take place.		  
               
  For the best results  
 
  1. Ensure that sufficient urine is absorbed by the test strip or midstream tip as per the test instructions.
  2. Do not allow urine to touch the test area (where you read the results). Allow the urine to flow along the test as per the instructions.
  3. For test strips, do not dip the strip below the submersion mark on the test strip or arrow line.
  4. When using a midstream test, hold the test so the test area (window) is facing away from your stream of urine.
  5. For cassettes drop four drops of urine into the test area (round well) of the cassette marked with an arrow.
  
  How do I interpret pregnancy test results?      
 
         
               
  Once the reaction time of the test is complete (15 minutes), a colour band or colour bands will appear (or fail to appear) in the test region
 of the strip or midstream test. All tests have a "control" colour band (or colour line) that indicates whether the test is working or not and
 must appear.		  
               
  The "test" colour band indicates a positive or negative result. A faint line in the test region should be read as a positive result. To confirm a
faint line verify the result with an additional test 24-48 hours later (using first morning urine). All positive test results should be followed up
with a consultation with your doctor to confirm pregnancy.		  
 
Client SurveyCape Town
    Back To Top    
 
  Home | About us | Contact
Copyright © Humor Diagnostica