Urine pregnancy test kits are quick and easy to use. The presence of hCG is manifested in color changes, traditionally visualized by the appearance of streaks. Newer digital tests display them with the words “Pregnant” or “Not Pregnant”.
There are several types of urine pregnancy tests, which you can buy over the counter at a drugstore or supermarket. Some digital kits are more accurate than traditional test kits.
With most tests, you hold the end of a chemical stick (the “stick”) in your urine stream or collect the urine in a container and test it. The auction measures hCG and uses colors or symbols to show whether or not you are pregnant. For example, they may show a pink or blue line or a “+” or “-” sign to show pregnancy. Digital auctions may indicate the words “pregnant” or “not pregnant” and may be easier to read.
Most urine pregnancy tests can detect hCG in urine on the first day of your expected period. But for the most reliable results, wait at least a week after your expected period before testing.
It is advisable to collect the urine sample first thing in the morning, preferably before drinking a lot of fluids. Read the instructions carefully before testing.
If the test is negative but your period still doesn’t come, you can try again in a few days.
If the test is positive , it is very likely that you are pregnant. It will only be in very rare circumstances that you will get a false positive result.
The types of urine pregnancy tests
Basically there are three different types of tests: the traditional ones, the digital ones, the so-called «early» ones.
All three of these typologies provide only a qualitative analysis . Let’s look at them one by one briefly.
The traditional pregnancy test
- And the classic one, the most used one.
- It has a reliability that generally stands at 99%.
- It has one or two control windows which must be interpreted according to the manufacturer’s instructions.
- It must be done starting from the days when the period should arrive.
The digital pregnancy test
- Unlike the traditional one, the digital one provides the results through a writing (which could be) “not pregnant” or “pregnant”, for example.
- In some cases, the digital test is able to estimate the age of the fetus by measuring the dosage of HGC levels, but this is not a reliable system.
- As with the traditional system, the digital test must also be done starting from the days when menstruation should arrive.
Early pregnancy test
- Unlike the two methods just described, the one used for early measurements uses a more sensitive system for detecting the amount of hormones in the urine.
- In fact it is able to detect even very small quantities of hgc (25 mU/ml vs 35 mU/ml of a traditional system).
- Unlike the two methods described above, the early test can be done 3-4 days before the expected date of arrival of menstruation.
Urine pregnancy test with weeks indication
Some home pregnancy test kits are also able to quantify the level of hCG present in urine so that women can also be given an estimate of how long they will be pregnant (in weeks after gestation).
This is the case with the Clearblue digital test.
For example, the “Clearblue™ Pregnancy Test With Weeks Indicator” by SPD Swiss Precision Diagnostics GmbH, Switzerland) can measure the hCG level and also indicate how many weeks since conception occurred: from 1- 2 weeks, from 2-3 weeks and from as early as 3 weeks after ovulation / conception. This test is based on the close relationship between human chorionic gonadotropin hCG and gestational age.
The test results have been shown to agree well (> 90%) with results for gestational age calculated using measurements of crown-nose length (CRL: the maximum length of the embryo, excluding limbs) of 11-13 weeks and the duration of pregnancy calculated based on ovulation.
Katherine Johnson, M.D., is a board-certified obstetrician-gynecologist with clinical expertise in general obstetrics and gynecology, family planning, women’s health, and gynecology.
She is affiliated with the Obstetrics and Gynecology division at an undisclosed healthcare institution and the online platform, Maternicity.com.