Pregnancy Blood Test: Quantitative vs Qualitative hCG, and What Comes Next

A pregnancy blood test checks your blood for human chorionic gonadotropin (hCG), a hormone the placenta starts making after a fertilized egg attaches to the inside wall of the uterus.¹ A qualitative hCG blood test tells you whether you are pregnant, and a quantitative test measures exactly how much hCG is in your blood.¹ This page explains the two types, how blood tests compare with urine tests, what results generally mean, and why folic acid matters from the moment you get a positive result.

What is a pregnancy blood test?

Pregnancy tests look for hCG in urine or blood.¹ Once the placenta begins making hCG, levels keep rising for about ten weeks, almost doubling every three days.¹ hCG helps the body prepare for pregnancy by signaling it to produce progesterone, which thickens the uterine lining, and estrogen, and by stopping menstrual periods.¹

hCG can appear in the blood and urine as early as 10 days after conception.² A blood test is always done at a provider's office or a lab: a health care professional draws a small sample from a vein in your arm, which usually takes less than five minutes.¹

Other names you may see on an order or report include hCG test, beta-hCG, quantitative hCG blood test, qualitative hCG blood test, and total chorionic gonadotropin.¹²

Quantitative vs qualitative hCG blood tests

There are two types of hCG blood test.¹

Quantitative hCG is also part of some prenatal screening panels (the "triple" or "quadruple" screen), and it is used to help diagnose or monitor some conditions unrelated to pregnancy, such as ovarian and testicular cancer.¹

Blood test vs urine test

Both tests detect the same hormone. The differences are sensitivity, cost, and speed.¹

Because urine tests are cheaper, very accurate, and faster, blood tests are not commonly used just to check for pregnancy.¹ They are more often ordered when an exact hCG level matters, such as when there are symptoms of an ectopic pregnancy or a high risk of miscarriage.¹

Getting the most accurate home result

If you test at home first, check the expiration date, read whether your test has a control symbol, use first morning urine (it usually has more hCG), and use a timer.¹ Avoid drinking large amounts of fluid beforehand, because it can dilute hCG.¹

When a quantitative hCG blood test is used

A provider may order a quantitative test if you:¹

• Are at high risk for miscarriage (common risk factors include active infections, thyroid disease, uncontrolled diabetes, obesity, and uterus or cervix problems)
• Have symptoms of an ectopic pregnancy, such as abnormal vaginal bleeding, pain in the lower back or abdomen, or cramping on one side of the pelvis
• Have symptoms of a molar pregnancy, such as abnormal vaginal bleeding, pelvic or abdominal pain, high blood pressure, or severe nausea

An ectopic pregnancy, in which a fertilized egg tries to grow outside the uterus, can be a medical emergency.¹ Seek care promptly for these symptoms.

You may also need a pregnancy test to confirm you are not pregnant before a medical treatment or procedure that could harm a fetus, such as the HSG fertility test.¹³

What do pregnancy blood test results mean?

A positive result means hCG was found, which usually means you are pregnant.¹ A negative result means hCG was not found, but testing too early can give a false negative because hCG may not yet be high enough.¹ False positives can also happen, for example while taking fertility medicines.¹

For quantitative tests, MedlinePlus lists these reference points, while noting that normal ranges vary among laboratories:²

Notice how wide the pregnancy ranges are. hCG rises rapidly during the first trimester and then declines slightly, and the expected range depends on how far along the pregnancy is.² A level higher than expected can occur with more than one fetus, and a level lower than expected for the stage of pregnancy can be associated with miscarriage or ectopic pregnancy, among other causes.²

Positive blood pregnancy test: what to do next

If your result is positive, see your provider as soon as possible so you can start prenatal care.¹ If you had a positive home test, your provider may repeat the test to confirm it.¹ Make a list of every medicine and supplement you take to review at that first visit.⁴

Anemia is common in pregnancy, so expect blood tests at different stages to check for it.⁵ Our guides to the CBC blood test and the ferritin blood test explain what those results show.

Folic acid after a positive pregnancy test

Folic acid is the most time-sensitive nutrient in early pregnancy. The embryonic neural tube normally closes about 26 to 28 days after fertilization, often before a pregnancy is recognized.⁶⁷ Starting folic acid only after a positive test may miss part of that window, but if you have not started, begin right away rather than concluding it is too late.⁶⁷

CDC recommends 400 mcg of folic acid every day for everyone who could become pregnant, from supplements, fortified foods, or both.⁸¹¹ ACOG advises most people to use a prenatal vitamin with at least 400 mcg of folic acid.¹² Folic acid is the only form of folate shown in studies to help prevent neural tube defects, so check the Supplement Facts panel for the words "folic acid".¹⁰⁸

Neural tube defects include spina bifida, anencephaly, and encephalocele.⁹ Our page on neural tube defects explains them in more detail. For doses at every stage, see how much folic acid to take for pregnancy, and if you are planning ahead for a future pregnancy, folic acid before pregnancy.

When to talk to a clinician

Your provider will explain what your hCG result means for you and set up the next steps in prenatal care.¹²

This article is for general education and is not medical advice. Doses and needs differ from person to person, so talk with your clinician or pharmacist about your situation. Read our editorial policy and medical disclaimer.