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Understanding hCG

Understanding hCG

Human chorionic gonadotropin is abbreviated as hCG. It is a hormone that is produced during pregnancy by the placental cells so, it is also known as pregnancy hormone. The placenta is an organ that attaches your unborn baby to the uterus and supplies oxygen and nutrients to your baby through the blood supply. hCG levels can be determined either by doing blood or urine test.

After conception, the fertilization of an egg by a sperm cell, the fertilized egg is transported from the fallopian tube to uterus, and attaches to the uterine wall. This process is called as implantation and occurs within 7 days after fertilization. Soon after implantation, the placental tissue starts secreting the hCG hormone and is released into the blood and urine within 6 days after implantation. hCG hormone stimulates corpus luteum for producing progesterone hormone. This progesterone hormone helps in supporting and nourishing the endometrial lining, where the embryo is implanted. Therefore, hCG hormone maintains uterine lining and helps in sustaining pregnancy

The normal levels of hCG hormone in a pregnant woman ranges from 5-117,000 mIU/mL. During the first trimester, the hCG levels increases rapidly for every 2-3 days. However, it can be detected in the blood 3-4 days after the implantation of your unborn baby in the uterus. Whereas, in the urine the hCG hormone can be detected 7 - 11 days after the implantation. Therefore, it is ideal to take urine test on the first day of missed periods.

The hCG levels may vary in each pregnant women depending on their physiology and the number of embryos they are carrying. Here is a chart which will helps you to understand the normal range of hCG during different weeks of pregnancy.

Condition hCG levels
Non-Pregnant < 5 mIU/ml.
3 weeks pregnant 5-50 mlU/ml
4 weeks pregnant 5-426 mlU/ml
5 weeks pregnant 18-7,340 mlU/ml
6 weeks pregnant 1,080-56,500 mlU/ml
7-8 weeks pregnant 7,650-229,000 mlU/ml
9-12 weeks pregnant 25,700-288,000 mlU/ml
13-16 weeks pregnant 13,300-254,000 mlU/ml
17-24 weeks pregnant 4,060-165,400 mlU/ml
25-40 weeks pregnant 3,640-117,000 mlU/ml

From the chart, it is evident that the hCG levels rapidly increase during the first trimester (1-12 weeks) of pregnancy. Due to this, you experience major changes and symptoms of pregnancy like nausea and vomiting. However, the hCG levels starts decreasing from 2 trimester (13-24 weeks) and 3 trimester ( 25-40 week) of pregnancy.

hCG levels just helps to detect pregnancy they does not helps to predict the gestation period and you baby's growth accurately. To find the gestation age and baby's growth you should have an ultrasound scan with the prescription of a gynecologist. So, do not get panic if you find that your hCG levels are not same as that of your friend who is/was pregnant.