The prospect of pregnancy is greeted with either joy or dread .Regardless of the emotion what one can do is to be sure. A late menstrual period is usually the first tell tale sign of pregnancy. However stress and many chronic illnesses can cause a delay in the onset of menses, so it’s not a reliable precursor until at least two week as after the expected date. Pregnancy tests detect the presence of the hormone called human chorionic gonadotropin (HCG) in the blood or urine .The hormone is secreted by the placenta shortly after the embryo attaches to the uterus lining. Quantitative blood tests are known to detect HCG traces as low as 1 mlU/mL Urine tests are less sensitive and a have a threshold detection of 20 mlU/mL and 100 mlU/mL.
Home pregnancy test using a pregcolor card and is one of the easiest methods of detecting pregnancy. Pregcolor cards in the market today vary widely in sensitivity. Some cards detect pregnancy one day after missed period while some take upto two weeks. Home tests are typically done in the morning when the concentration of HCG is the highest. There are tests which give you results in a minute while others take upto 2 hrs.
Care to be taken before testing
>>Pregcolor cards are usually stored in refrigerator; they must be brought to room temperature using them.
>>Ensure that the urine is collected in a clean glass with no detergent residue.
>>Care should be taken not to spill the urine on the reading strip
>>Read the test result within the reaction time given in the instructions slip, reading too early or tool late can both result in inaccurate reading.
Though home pregnancy tests are sensitive and accurate it is still possible to get a false positive or negative. There are a variety of factors which can lead to a false result
> Evaporation lines may appear if the results are read after the 3- 5 minute reaction time mentioned.
>A women given an injection of HCG as part of infertility treatment may test a false positive
>> Drinking too much water may dilute the urine and the card may fail to detect the faint trace of HCG.
>> The test may show a false negative if done too early as the urine may not have enough HCG for the strip to detect.
A Pregnancy test measures the exact amount of HCG in a women’s blood. Pregnancy blood tests can detect pregnancy earlier than a home test. Blood tests are more accurate than home tests though not necessarily more sensitive. Quantitative blood test measures the exact amount of HCG while Qualitative blood test just says whether a woman is pregnant or not.