Definition

A pregnancy test is a diagnostic procedure aimed at determining whether a pregnancy has occurred. The test detects the presence of the β-hCG hormone, which is produced only during pregnancy. This hormone is synthesized by placental tissue, which forms once the fertilized egg attaches to the uterine wall. During pregnancy, β-hCG levels rise significantly during the first trimester, peaking around the 8th to 10th week. After the 12th week, these levels gradually decline.

Beyond confirming pregnancy, the β-hCG hormone can also be used to identify other medical conditions such as ectopic pregnancy, monitor cases of suspected miscarriage, or diagnose uterine malignancies. This hormone can be detected in both urine and blood, making pregnancy tests available in two formats, urine-based test and blood-based test.

Urine pregnancy tests can be performed independently at home using a test pack or at a clinic after consulting with a doctor. Test packs are designed to detect β-hCG levels in the urine as early as the 3rd week of pregnancy or one week after a missed menstrual period. When used correctly, urine tests provide an accuracy of 97–99%. Advantages of urine pregnancy tests include affordability, ease of use, and can be used independently at home.

Blood pregnancy tests are conducted at healthcare facilities where trained medical professionals collect blood samples. These tests measure the exact β-hCG levels in the bloodstream and can detect pregnancy earlier than urine tests, typically 6–12 days after unprotected sex. Advantages of blood pregnancy tests include higher accuracy, approximately 99%, and it can be used to confirm pregnancy earlier than urine tests. Blood test is also useful as a follow-up test to confirm doubtful urine test results. However, blood tests are more expensive and require clinical assistance, making them less convenient than urine tests.

Indications

A pregnancy test is recommended when pregnancy is suspected in women of childbearing age, particularly those who have had unprotected sex or used contraception inconsistently.

Common signs of pregnancy that warrant confirmation with a test include:

• Missed menstrual period.
• Morning sickness (nausea and vomiting).
• Sore or enlarged breasts.
• Abdominal cramps or pain.
• Brown vaginal discharge.
• Decreased appetite.
• Mood swings.
• Fatigue.

Contraindications

There are no contraindications or conditions that prevent someone from undergoing a pregnancy test.

Preparation Prior to Test

There is no special preparation required before taking a pregnancy test. However, certain medications can influence the test results. Drugs commonly used in IVF (in vitro fertilization) or insemination programs, which contain synthetic β-hCG hormones, may lead to false positive results.

Examples of such medications include Pregnyl, Ovidrel, and Novarel, which are used to trigger ovulation and enhance fertility. The synthetic β-hCG hormone from these drugs typically clears the body within 10 days to 2 weeks. To avoid false positives, it is recommended to wait at least 2 weeks after taking these medications before performing a pregnancy test.

Test Procedure

The procedure for a pregnancy test depends on whether you are using a urine-based or blood-based test. To ensure accurate results when using a urine test pack, follow these steps:

• Verify that the test pack is not expired or damaged.
• Use the first urine of the day, as it contains the highest levels of β-hcG hormone.
• Use the test pack either by placing it directly in the urine stream or by dipping it into urine collected in a clean container.
• Wait a few minutes for the test to process.
• Check the lines that appear on the test pack. One line means the result is negative, meanwhile, two lines indicate the result is positive

A blood pregnancy test is conducted at a healthcare facility. A medical professional will collect a blood sample from a vein using a syringe. The sample is then analyzed in a laboratory to measure β-hcG hormone levels in the blood.

Normal and Abnormal Values

The results of a urine pregnancy test are determined by the appearance of lines on the test pack. If one line appears, it indicates a negative test result, meaning no pregnancy. If two lines appear, it indicates a positive test result, suggesting pregnancy.

In contrast, a blood pregnancy test measures the level of the β-hcG hormone in the bloodstream. The normal β-hcG hormone level in healthy women who are not pregnant is less than 5 mIU/mL, while in healthy men, the normal value is less than 2 mIU/mL. During pregnancy, the β-hcG hormone level increases progressively in accordance with gestational age.

Abnormal values occur when the β-hcG hormone levels are either higher or lower than normal limits. Such deviations may signal the presence of other medical conditions that require further investigation.

Results and Recommendation (Follow-up Tests)

Consult the Right Doctor

If your urine pregnancy test shows a positive result, consult an obstetrician for a physical examination and additional tests such as an ultrasound. Similarly, seek medical advice if blood β-hcG hormone levels are outside normal ranges, particularly if accompanied by severe abdominal pain or vaginal bleeding. These symptoms could indicate serious medical conditions requiring prompt treatment.

Looking for more information about laboratory, radiology, and other examination results? Click here!