Beta hCG Levels Week by Week: What's Normal?

If you've had beta hCG blood tests during early pregnancy, you're probably staring at numbers wondering what they mean. Are your levels normal? Should they be higher? Lower? This guide breaks down hCG levels week by week so you know what to expect.

What is Beta hCG?

Beta hCG (human chorionic gonadotropin) is the hormone produced by the developing placenta after the embryo implants in your uterus. It's what pregnancy tests detect. The "beta" refers to the specific subunit of the hormone that blood tests measure.

Your body starts producing hCG right after implantation, typically 6-12 days after ovulation. From there, levels rise exponentially during the first trimester, roughly doubling every 48-72 hours in healthy early pregnancy. This rapid rise supports the pregnancy until the placenta can fully take over hormone production around 10-12 weeks.

Normal hCG Levels by Week (from LMP)

These ranges show typical hCG levels measured in mIU/ml (milli-international units per milliliter). Remember that ranges are very wide because every pregnancy is different.

Notice how wide these ranges are. One woman's hCG at 5 weeks might be 100, while another's is 5,000 - both perfectly normal. This is why a single hCG number doesn't tell your doctor much. What matters is the pattern over time.

hCG Doubling Time: What's Normal?

In early pregnancy, hCG should roughly double every 48-72 hours. Your doctor will typically order two tests 48-72 hours apart to check if levels are rising appropriately. Here's how doubling time varies by starting level:

• hCG below 1,200: Doubles every 48-72 hours (most pregnancies)
• hCG 1,200-6,000: Doubles every 72-96 hours (still normal)
• hCG above 6,000: Doubling time increases beyond 96 hours (expected)

Once hCG exceeds 6,000-10,000, your doctor usually switches to ultrasound for monitoring instead of blood tests. By this point, ultrasound provides better information about pregnancy viability than hCG numbers.

What Do Low hCG Levels Mean?

Low hCG for your gestational age can indicate several things:

Miscalculated Due Date

The most common reason for "low" hCG is that you're not as far along as you thought. If you ovulated late or have irregular cycles, your conception date might be off by a week or more. A dating ultrasound clarifies this.

Ectopic Pregnancy

In ectopic pregnancy (when the embryo implants outside the uterus), hCG typically rises more slowly than expected. Instead of doubling every 48-72 hours, it might rise by only 50-60%. Ectopic pregnancy requires immediate medical attention. If you have lower abdominal pain, shoulder pain, or bleeding along with slowly rising hCG, call your doctor right away.

Impending Miscarriage

When a pregnancy isn't viable, hCG may plateau or start declining. Falling hCG levels indicate pregnancy loss. Your doctor will likely order an ultrasound and possibly repeat blood work to confirm.

Blighted Ovum

Sometimes the gestational sac develops but an embryo doesn't form. hCG may rise normally at first, then plateau earlier than expected. Ultrasound after 6-7 weeks can diagnose this.

What Do High hCG Levels Mean?

hCG levels on the higher end of the normal range might mean:

Twins or Multiples

Twin pregnancies often (but not always) have higher hCG levels than singleton pregnancies. However, ranges overlap too much to diagnose twins from hCG alone. One twin pregnancy might have lower hCG than a singleton pregnancy. Only ultrasound can confirm multiples.

Molar Pregnancy

This rare condition causes extremely high hCG levels - often much higher than even twin pregnancies. Molar pregnancy happens when abnormal tissue grows in the uterus instead of a normal embryo. It's diagnosed by ultrasound.

Miscalculated Dates

Just as low hCG might mean you're not as far along, high hCG might mean you're further along than calculated. Early ovulation can throw off dating by a week or more.

When to Worry About hCG Levels

Contact your healthcare provider if:

• Your hCG is doubling slower than every 72 hours (when levels are below 1,200)
• Your hCG level is falling instead of rising
• You have pain or bleeding along with slowly rising hCG
• Your hCG is extremely high for your gestational age
• Your provider tells you your level is concerning

That said, some healthy pregnancies have slower-than-average doubling times or start with lower numbers. The overall pattern matters more than a single number. Your doctor will use hCG trends plus ultrasound to assess your pregnancy.

Why Aren't All Pregnancies Monitored with hCG?

Most healthy pregnancies don't need serial hCG testing. Blood tests are typically ordered when:

• You had IVF or fertility treatment
• You've had previous miscarriages or ectopic pregnancy
• You're experiencing bleeding or cramping
• Your first hCG level was concerning
• Your doctor can't confirm pregnancy location on early ultrasound

For uncomplicated pregnancies, your doctor will schedule an ultrasound around 7-8 weeks to confirm a heartbeat and due date. That ultrasound provides more information than hCG numbers can.

hCG After Miscarriage

After a miscarriage, hCG levels fall gradually. How fast depends on how high they were at the time of loss. It might take several weeks for hCG to drop back to non-pregnant levels (below 5 mIU/ml).

Your doctor will monitor hCG back to zero to ensure the miscarriage is complete. If hCG plateaus or stops declining, you might need medication or a procedure to complete the miscarriage.

Using Our hCG Calculator

Our hCG calculator helps you track doubling time between two blood tests. Enter your hCG values and test dates to see if your levels are rising appropriately. The calculator compares your doubling time to normal ranges and provides guidance on what the pattern means.

The Bottom Line

hCG levels vary wildly between healthy pregnancies. A single number doesn't predict pregnancy outcome. What matters is the trend - whether levels are doubling appropriately for your starting level. If you're having serial hCG tests, try not to stress over individual numbers. Your healthcare provider will interpret the overall pattern.

Remember that by 6-8 weeks, ultrasound becomes much more informative than blood tests. Seeing a heartbeat on ultrasound is far more reassuring than any hCG number.

Related Tools & Resources