HCG Levels in Pregnancy

The following information is from Anne Frye (CPM)'s book: "Understanding Diagnostic Tests in the Childbearing Year" 6th edition

p. 108 "Normal hCG Levels in Early Pregnancy"

"HCG is detectable in the blood serum of approximately 5% of pregnant women by 8 days after conception, and in virtually all the rest by 11 days. HCG rises progressively from conception. Levels double on the average, every 30.9 hours until values reach 6500 mIU/ml (6,500 IU/L) at approximately the eighth week after the last menstrual period (LMP). After that the rate of rise becomes individualized, peaking between the 60th and 70th day (9 to 10 weeks) LMP. HCG decreases slightly between the 12th and 16th week post LMP, and then remains constant until birth. "

p. 111 "To Diagnose Pregnancy"

"A blood serum level of less than 5 mIU/ml (5 IU/L) can be considered negative and anything above 25 mIU/ml (25 IU/L) positive for pregnancy. If you are unsure, repeat the test in two days to see if there is an upward trend, which indicates pregnancy."

"Levels higher than expected for the weeks pregnant may be due to multiple gestation or inaccurate dates. ... Levels for normal pregnancy fall within the following wide ranges. You will note a discrepancy between the ranges of normal in the two tables below. The actual level can vary widely, and is not as significant as the amount and rate of rise, particularly before 10 weeks."

p. 112

PREGNANCY STATUS SERUM hCG LEVELS

from conception	from LMP	(mIU/ML or IU/L)
7 days	3 weeks	0 to 5
14 days	28 days	3 to 426
21 days	35 days	18 to 7,340
28 days	42 days	1080 to 56,500
35 - 42 days	49 - 56 days	7,650 to 229,000
43 - 64 days	57 - 78 days	25,700 to 288,000
57 - 78 days	79 - 100 days	13,300 to 253,000
17 - 24 weeks	2nd trimester	4060 to 65,400
25 wks to term	3rd trimester	3640 to 117,000
After several days postpartum		nonpregnant levels (<5)"

"Results in Twin Gestation"

"Quanitative serum hCG tests detect multiple pregnancy approximately 9 weeks earlier than ultrasound. One small study (Jovanovic, 1977) found hCG levels in 15 singleton and 9 twin pregnancies were as follows:

DAYS FROM LMP hCG in SINGLTON AVERAGE GESTATION RANGE hCG in AVERAGE TWIN GESTATION RANGE
28 64.7 9.4 to 120 64.7 9.5 to 120
33 450 300 - 600 1,500 200 to 1,800
36 1,500 1,200 - 1,800 19,200 2,400 to 36,000
40 3,600 2,400 - 4,800 58,344 8,700 to 108,000
45 36,000 12,000 - 60,000 126,000 72,000 to 180,000
70 120,000 96,000 - 144,000 414,000 348,000 to 480,000"

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