A missed period always fills up a woman with anxiety, either anticipatory anxiety of a planned pregnancy or bordering on to panic if she does not want the pregnancy. For those caught in the dilemma, it is mandatory to know that menstruation could be delayed for several causes, pregnancy being one of them. But a missed period, in a sexually active woman is pregnancy unless proved otherwise.
The tablets available earlier, which a woman could take in case of a missed period was just a means of diagnosing pregnancy. They contained Estrogen & Progesterone (the female hormones) and caused withdrawal bleed. The hormones could prove detrimental if pregnancy is continued and also take almost 10-12 days before one can be reasonably certain.
There are various ways to confirm pregnancy, depending on the urgency. For example in a woman with bad obstetric history in past, her doctor may want to confirm as soon as possible. Whatever the test, principle remains the same.
A hormone called human chorionic gonadotrophin (hCG) is produced soon after conception, even before the fertilized egg is embedded in the wall of the uterus. The concentration of this hormone is enough to suppress the next menstrual cycle and by 35th day is high enough to be detected in the urine. Early in the pregnancy it is advisable to test a morning sample as HCG concentration is maximum this being a concentrated sample.
A positive test is indicative of pregnancy in more than 90% of the cases but it is important to remember that a negative result very early in pregnancy with some signs and symptoms of pregnancy, calls for a repeat test after seven days.
In the urine test, when urine of a pregnant woman is added to a solution containing antibodies to hCG the two react and the color of the solution changes. This confirms pregnancy. In the absence of color change, pregnancy is ruled out. While doing Beta-hCG levels of the hormone are measured and the reading is then compared with normal values.
WHEN CAN THE TEST BE DONE?
This urine test should be preferably done after 5 days and within 14 days of a missed period. Today sensitive kits are available which detect even minute quantities of hCG and confirmation can be had within 48 hours of a missed period. Beta-hCG can even be done before the due date. All these periods are valid ONLY if your menstruation is regular. The urine test is not reliable after 12 weeks of a missed period when methods like sonography should be used.
HOW SHOULD ONE COLLECT THE URINE?
The first morning urine sample should be collected in a clean container. Why a morning sample? Likely to have higher concentration of hCG. The test should be performed within 12 hours.
CAN I DO THIS TEST AT HOME?
Yes, you can! There are test kits available in our country costing approx Rs. 45/-. All you have to do is add a few drops of urine to the solution provided and it will change color if you are pregnant. But you must read the result after 30 minutes waiting period. It is okay if the test is positive but a negative result should be discussed with your family physician.
FALSE NEGATIVE URINE TEST
In case of irregular periods or late pregnancy, a urine test done after 5 days may be negative. If you are looking forward to the pregnancy, do not take any tablets and repeat the test after 5 days or go in for a blood test
Beta component of hCG can also be detected in the
blood of the patient if early confirmation is very important.
It is very difficult to detect pregnancy with just clinical examination before the end of the eight weeks of pregnancy. That is why alternate methods are deployed. Beta component of hCG can also be detected in the blood of the patient if early confirmation is very important.
Changes in the reproductive organs that can be detected by clinical examination after about eight weeks of pregnancy include: