Should I Worry If My Early Pregnancy hCG Level Is Low?

Find Out What It Means When Your hCG Level is Low or Not Increasing

Doctor using ultrasound on pregnant woman
Getty Images/Chris Sattlberger

During pregnancy, your body produces a hormone called human chorionic gonadotropin (hCG). In a normal pregnancy, the level of hCG in your blood should increase significantly (by at least 60%) and, ideally, double in two quantitative hCG blood tests given by your doctor that are spaced over two to three days in early pregnancy.

The Normal Rate of Increase in Early Pregnancy

If your hCG level doubles in that way, it's generally a signal that your pregnancy is moving along smoothly.

The hormone tends to double at that rate—every two to three days—during the first four weeks or so of gestation, but, as your pregnancy goes on, it takes a longer period of time for your hCG level to double. For instance, around week six or seven, it may take three and a half days for hCG to double. Between week eight and week 11, hCG tends to stop rising altogether.

Low hCG Levels or Slow Rise in hCG

If your hCG level is rising slowly during those first four weeks of pregnancy, it can sometimes be a red flag that something is going wrong with the pregnancy. For instance, it can signal a miscarriage or an ectopic pregnancy, which happens when a fertilized egg implants outside the uterus, like in the fallopian tubes, and does not survive. But a slow-rising hCG level during the first four weeks isn't always cause for alarm. According to the American Pregnancy Association, a slow-rising hCG level is present in roughly 15% of pregnancies.

When hCG Levels Decrease in Early Pregnancy

An hCG level that doesn't just slow but actually decreases early on in the pregnancy is concerning. Any hCG level that decreases in the first trimester is nearly always a sign of miscarriage.

Remember to talk to your doctor if you are concerned about an hCG level that is not doubling.

And look out for common signs of miscarriage and ectopic pregnancy.

Common miscarriage symptoms include:

  • Vaginal bleeding
  • Painful cramping
  • Passing tissue through the vagina
  • Fewer or no more pregnancy symptoms (like nausea, sore breasts, and a missed period).

Rates of miscarriage vary, depending on age, but generally speaking, the higher your maternal age, the higher your rate of miscarriage. You have a 15% risk before age 35 and after age 45, you have up to a 50% chance of miscarrying, according to the American Pregnancy Association.

Common symptoms of ectopic pregnancy are often similar to those of a miscarriage and include:

  • Vaginal bleeding
  • Abdominal or pelvic pain
  • Lightheadedness or fainting
  • Shoulder pain
  • Urge to have a bowel movement.

If you are experiencing an ectopic pregnancy, a pregnancy test will still show a positive result and you'll still likely have typical symptoms of pregnancy, such as nausea, sore breasts, and a missed period. Roughly 1 in 50 pregnancies is ectopic, the American Pregnancy Association reports.

When to Call Your Doctor

If you notice any of these symptoms, call your doctor immediately. If there is any concern about miscarriage or ectopic pregnancy, your doctor will likely perform an ultrasound and a pelvic exam to obtain further information about the health of your pregnancy. About halfway through your first trimester, an ultrasound (also known as a sonogram), for example, will show a growing fetus that has a visible heartbeat if your pregnancy is viable.

Sources:

American Pregnancy Association, "Human Chorionic Gonadotropin (hCG): The Pregnancy Hormone." July 2007. Accessed 17 Jan 2008.

"Miscarriage: Signs, Symptoms, Treatment and Prevention." American College of Obstetricians and Gynecologists (2015).

"Ectopic Pregnancy: Symptoms, Causes, Risks And Treatment." American College of Obstetricians and Gynecologists (2015).

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