HCG Levels Chart: Are They Necessary While Pregnant?
While you don’t need to track hCG throughout you nine-month gestation, an hCG levels chart can inform doctors about the health of your pregnancy.
During pregnancy, hCG (human chorionic gonadotropin) is released from cells in the placenta. The hormone circulates through the body, and it can be detected in blood and urine, says Maureen Baldwin, M.D., MPH, an assistant professor of Obstetrics and Gynecology at Oregon Health and Science University.
Tracking hCG levels in early pregnancy can ensure the fetus is developing properly. Even so, it’s unnecessary to monitor hCG throughout your entire nine-month gestation, since hCG levels plateau around 8-10 weeks after implantation. Here’s everything you need to know using an hCG levels chart.
hCG Levels in Early Pregnancy
In a normal pregnancy, the placenta starts releasing hCG about 6-12 days after ovulation. The levels usually double every 29-53 hours, says Dr. Brennan Lang, an Ob-Gyn at Baylor Obstetrics and Gynecology at Texas Children’s Pavilion for Women. This trend continues until 8-10 weeks after implantation, when hCG levels peak at around 90,000-100,000 mIU/mL. Then hCG starts plateauing – probably because the placenta takes over estrogen and progesterone production, experts theorize.
But here’s the tricky part: healthy hCG levels don’t always double every two days. "The level of hCG detectable in blood tests increases rapidly in early pregnancy at a rate of about 35% to 200% or more every two days, which is a wide range of normal,” says Dr. Balwin. That’s why doctors don’t pay much attention to specific hCG numbers; instead, they focus on hCG trends.
A normal pregnancy will show a steady increase of hCG in the first several weeks of pregnancy. Moderately low or high numbers may simply indicate a miscalculated conception date–meaning the pregnancy is older or younger than previously thought. But unusual trends raise red flags. Dr. Lang says hCG levels that are falling, plateauing, or rising abnormally slow could indicate miscarriage, blighted ovum, or ectopic pregnancy. On the other hand, extremely high hCG levels may signal placental tumor, molar pregnancy, or pregnancy with multiples.
Tracking hCG Levels by Week
While home pregnancy tests alert you to the presence of hCG, they don’t gauge exact levels of the hormone. For that information, you’ll need a blood test from your doctor. “Urine tests are very sensitive and will turn positive at low levels of usually 25, 50, or 100 mIU/mL, which can all detect pregnancy in the week after a missed period,” says Dr. Baldwin. “Blood tests can give a concentration of the hormone and are pretty accurate, even from lab to lab.”
At your first prenatal appointment, your doctor will test hCG levels to confirm your pregnancy. But she probably won’t monitor hCG levels too closely at future appointments. According to Dr. Baldwin, “we almost never will find a single hCG blood test useful and it is usually not necessary to get an hCG blood test in early normal pregnancy.” That’s because hCG levels vary greatly, and one number won’t let you know if the baby is thriving.
There’s one exception to this general rule, however. Doctor may track hCG if they’re concerned about your pregnancy health – for example, if you’re bleeding, cramping, or showing other signs of miscarriage. According to Dr. Baldwin, subsequent tests are usually taken 48 hours apart, which lets doctors analyze trends in hCG levels. Rapidly rising, falling, or plateauing levels may require further testing.
After the pregnancy can be seen on ultrasound, doctors will probably stop measuring hCG altogether. At this point, “the best measure of a normally-growing pregnancy is the monitoring of uterine size by your provider,” says Dr. Baldwin. Adds Dr. Lang: “If a pelvic ultrasound shows a pregnancy inside the uterus with a heartbeat, there is no reason to keep checking hCG levels. They no longer predict the continuation of the pregnancy.”
hCG Levels Chart
This hCG levels chart shows typical numbers in early pregnancy, according to experts. Women should keep in mind that there’s a wide range of normal hCG levels.
3 Weeks from Last Missed Period (LMP) = hCG level of 5 – 50 milli-international units per milliliter (mIU/mL)
4 Weeks from LMP = 5 - 426 mIU/mL
5 Weeks from LMP = 18 - 7,340 mIU/mL
6 Weeks from LMP = 1,080 - 56,500 mIU/mL
7-8 Weeks from LMP = 7, 650 - 229,000 mIU/mL
9-12 Weeks from LMP = 25,700 - 288,000 mIU/mL
13-16 Weeks from LMP = 13,300 - 254,000 mIU/mL
17-24 Weeks from LMP = 4,060 - 165,400 mIU/mL
25-40 Weeks from LMP = 3,640 - 117,000 mIU/mL
Note that an hCG level greater than 25 mIU/mL can confirm a pregnancy. Women who aren’t pregnant typically have hCG levels less than 5 mIU/mL.