How do Pregnancy Tests Work?

Pregnancy tests identify a special hormone in the blood or urine produced during pregnancy. This hormone is called human chorionic gonadotropin (HCG), often referred to as the pregnancy hormone. There are two basic types of pregnancy tests, blood and urine.

Home pregnancy test are primarily urine tests. These are easy to use, private and inexpensive. Most are quick and very accurate, claiming a 99% accuracy rate. Tests can be purchased at drug and discount stores without a prescription. False positives are very rare, but a false negative is possible if the test is done too early for sufficient quantities of HCG in your urine. False negatives can be avoided by waiting until your period is due, or about 2 weeks after you ovulate. Confirming a negative result with a second test a few days or a week later is wise. Always follow a positive result with a trip to your doctor for confirmation and prenatal care.

Medicines containing HCG can cause a false positive on your home test, but most over-the-counter and prescription drugs will not affect test results.

Blood test results may take a few hours or a day, and usually require a trip to the doctor or lab. There are two types of blood tests for pregnancy. The first, a qualitative HCG blood test, provides simple positive or negative results, similar to a urine test. This test is slightly less accurate than the quantitative blood test (or beta HCG test) which measures the exact amount of HCG in the blood. The beta test's ability to pick up small traces of HCG in the blood increase its accuracy.

Whichever type of test you choose, it is important to remember that a follow-up trip to the doctor is important for you and your new baby.

Maria writes for Pregnancy Due Date, a site that tries to information for expectant mothers. For more great pregnancy articles, visit our Pregnancy articles archive.

In The News:


pen paper and inkwell


cat break through


Why Shouldnt I Smoke During Pregnancy?

There are a lot of good reasons to quit smoking,... Read More

Piece of Mind During Pregnancy - It is Possible with Babysheart

After four years of marriage my husband and I started... Read More

Pregnancy Fashion - Look And Feel Great During Your Pregnancy!

Have you ever wondered what makes women tick? Well among... Read More

Successful Weight Loss After Pregnancy

How fast you lose weight will depend on a number... Read More

Weight Gain During Pregnancy, and Weight Loss After Pregnancy

How much weight gain is normal during pregnancy, and will... Read More

How do Pregnancy Tests Work?

Pregnancy tests identify a special hormone in the blood or... Read More

Coping With an Unplanned Pregnancy

Your period is late and you start to think maybe... Read More

How to Get Your Pre-pregnancy Body Back

The second biggest question you will ask yourself as a... Read More

Feeling Sexy During Pregnancy

Some people think that the word sexy and pregnancy do... Read More

Smoking During Pregnancy

If you have been drinking up until the point when... Read More

The Myths of Fitness During Pregnancy - The Straight Facts on the ACOG Guidelines

The American College of Obstetics and Gynecology (ACOG) guidelines are... Read More

Expressing Breast Milk: Pumping for Your Preemie

The shock and stress of having a baby born prematurely... Read More

Vacation Is One Way To Run Away From Stress During Pregnancy

What should you do to have a happy pregnancy? Many... Read More

Vitamin C Prevents Pregnancy Complication

Women who supplement with a small amount of vitamin C... Read More

Baby Shower Gift Ideas

Selecting a present for a new mom or dad can... Read More

Mommy Is Having A Baby!

Preparing for a new arrival from the beginning of your... Read More

Planning a Healthy Pregnancy

Looking for healthy lifestyle pregnancy information? Here are some steps... Read More

Pregnant Mothers and Starbucks

Many mothers are addicted to caffeine and cannot handle going... Read More

You Can Do Exercise During Pregnancy, but Dont Overdo It

Don't get so lazy during your pregnancy. Move your body... Read More

Early Signs of Pregnancy

Think you may need to do a home pregnancy test?... Read More

Preparing for a Vaginal Birth after Cesarean

WHY LACK OF SUPPORT?Several years ago, ACOG, American College of... Read More

Foods To Avoid During Pregnancy

Many women have questions about the types of food that... Read More

Weight Loss After Pregnancy - The Importance Of Setting Goals

One of the best things you can do is set... Read More

Is Pregnancy Changes You?

People say pregnancy is a fun and exciting time. Probably... Read More

Stress And Pregnancy

Stress Relief During Pregnancy If you truly want to ensure... Read More

Pregnancy Weight Gain - The Mystery Solved

It is important that you remember that weight gain is... Read More

Why Pregnant Women Get Stressed and Depressed?

If you are a pregnant mother or soon will be,... Read More

Infertility and Pregnancy

When a couple is unable to conceive a child, it... Read More

Exclusively Pumping Breast Milk

It is commonly recognized that breast milk is the best... Read More

How To Avoid Swelling When Pregnant

Edema, otherwise known as swelling, will affect almost all women... Read More

Pregnancy And Celiac Disease

If you have celiac disease and are well controlled because... Read More

How Fast Will I Lose The Weight I Gained During Pregnancy?

Remember as with any weight loss and exercise program, moderation... Read More

Delight in Pregnancy Bedrest

My first experience with bedrest was at 30 weeks into... Read More