hCG Levels by Week: Early Pregnancy Chart and What Your Quantitative Blood Test Shows

Typical quantitative hCG ranges for a single pregnancy, in mIU/mL, counted in weeks from the first day of the last menstrual period (LMP). The ranges are wide on purpose: a "low" number for one woman is normal for another, and the implantation date alone shifts the whole curve by days.

Weeks from LMP	Typical hCG range (mIU/mL)
3 weeks	5 – 50
4 weeks	5 – 426
5 weeks	18 – 7,340
6 weeks	1,080 – 56,500
7 – 8 weeks	7,650 – 229,000
9 – 12 weeks	25,700 – 288,000
13 – 16 weeks	13,300 – 254,000
17 – 24 weeks	4,060 – 165,400
25 weeks to term	3,640 – 117,000
Not pregnant	below 5

Because the ranges overlap so much, a single hCG value cannot date a pregnancy. Dating is done by LMP and, from about six weeks, by ultrasound. Twins and higher-order pregnancies usually run higher, but hCG alone does not diagnose them either. What clinicians actually read is the change between two draws 48 hours apart — covered in the rise table below.

Human chorionic gonadotropin is made by the cells that become the placenta, beginning around the time the embryo implants — six to twelve days after ovulation. A home urine test detects hCG above a fixed threshold (usually 20–25 mIU/mL) and answers yes or no. A quantitative serum test measures the actual concentration, is sensitive to about 1–5 mIU/mL, and can therefore confirm pregnancy a few days earlier, at roughly 7–10 days after conception.

The number matters because it changes predictably. In a normally developing pregnancy hCG rises fast in the first weeks, peaks around weeks 8–11, then falls and plateaus for the rest of pregnancy. Two measurements 48 hours apart show whether the level is climbing as expected — which is why clinicians almost always order the quantitative test in pairs when there is a question about how the pregnancy is progressing.

The classic rule is doubling every 48–72 hours during the first four weeks after implantation, slowing to every 96 hours as the level passes about 6,000 mIU/mL. More recent data are less strict: in viable pregnancies the minimum 48-hour rise depends on the starting level — so a level that goes from 400 to 620 in two days is within normal even though it did not double.

Starting hCG (mIU/mL)	Minimum expected rise over 48 hours	Example
Under 1,500	About 35%	400 → at least 540
1,500 – 3,000	About 40%	2,000 → at least 2,800
Over 3,000	About 50%	4,000 → at least 6,000
Over about 6,000	Doubling slows to every ~96 hours	Plateau near the week 8–11 peak is normal

Once hCG is above about 1,500–2,000 mIU/mL, a transvaginal ultrasound should be able to see a gestational sac; this "discriminatory zone" is why a clinician who sees a high hCG with an empty uterus on ultrasound will look carefully for an ectopic pregnancy. Below the zone, ultrasound is often inconclusive and the paired blood tests do the work.

A result above the typical range for your week is usually explained by one of three ordinary things: the dates are off (an earlier ovulation than assumed puts you a week further along than the LMP suggests), a multiple pregnancy, or simple biological variation — the upper ends of the ranges above are high because healthy singleton pregnancies reach them. None of these needs action on its own; your clinician confirms dating and number with an ultrasound from about six weeks.

Less often, a very high level — or a level that keeps climbing past the usual week 8–11 peak — points to a molar pregnancy (gestational trophoblastic disease), which is diagnosed by ultrasound and followed with serial hCG. High hCG in the second trimester is also one of the inputs to prenatal screening calculations, where it is read together with other markers rather than on its own. A high value with severe nausea, bleeding or an unusually large uterus for dates is a reason to be seen promptly rather than to wait for the next draw.

A rise slower than the minimums above, a plateau, or a fall can indicate a pregnancy that is not developing normally — an early loss or an ectopic pregnancy — but no single pattern is diagnostic. About a third of ectopic pregnancies show a "normal" rise, and some healthy pregnancies start slowly. Clinicians combine the trend with symptoms (one-sided pelvic pain, shoulder-tip pain, dizziness, bleeding), the ultrasound, and sometimes progesterone before drawing conclusions.

After an early loss, hCG falls and typically returns below 5 mIU/mL within two to six weeks depending on how high it was; a level that stops falling is a reason to be seen, because retained tissue or a molar pregnancy can keep it elevated. After delivery it is undetectable within about four weeks.

Same-day care is warranted for severe or one-sided abdominal pain, heavy bleeding, fainting or shoulder pain in early pregnancy regardless of the hCG number.

Occasionally. Fertility medications that contain hCG (the "trigger shot") stay detectable for up to about 10–14 days. Certain tumours — gestational trophoblastic disease, some germ-cell tumours of the ovary or testis — produce hCG, which is why the same test is used as a tumour marker in men. Around menopause the pituitary can secrete small amounts, producing low positives in the 5–15 range. Very rarely, antibodies in the blood interfere with the assay ("phantom hCG"), which a lab can check by testing urine or diluting the sample. A positive result in a man or a postmenopausal woman should always be discussed with a clinician.