Normal HCG Levels By Week
When you first find out you're pregnant, you're excited because you're entering into a special time in your life—but you're also anxious, because you don't want something to go wrong. The majority of pregnancies unfold without complications. During the early stages of pregnancy, many women try to keep track of their HCG levels. What is HCG? This is a hormone which is produced in increasing amounts for your first 9-12 weeks in order to help your fetus to develop in a safe and comfortable environment. HCG stands for human chorionic gonadotropin. Its job is to maintain the corpus luteum, which in turn releases progesterone during the early part of pregnancy. Later the placenta takes over that job.
What are the normal HCG levels by week? When you are three weeks pregnant, as measured by your last menstrual period, your levels will be 5 - 50 mIU/ml. At four weeks pregnant, those levels increase to 5 - 426 mIU/ml. At five weeks pregnant, the normal levels for HCG are 18 - 7,340 mIU/ml. When you reach six weeks, your levels should measure 1,080 - 56,500 mIU/ml. At 7-8 weeks pregnant, levels increase to 7, 650 - 229,000 mIU/ml. You'll peak between 9-12 weeks at 25,700 - 288,000 mIU/ml.
After this, your levels will naturally start to drop. This is normal and expected. Standard readings at 13-16 weeks are 13,300 - 254,000 mIU/ml. At 17-24 weeks, normal HCG levels are 4,060 - 165,400 mIU/ml. As your pregnancy nears its end, 3,640 - 117,000 mIU/ml is typical. Shortly after you give birth to your new baby boy or girl, your levels will become undetectable in your blood and things will go back to the way they were before you were pregnant.
You'll notice that normal HCG levels by week can vary widely and still be considered normal and healthy. There are many reasons why you might find yourself trailing at the upper or lower end of the range. The most common reasons are natural variation or a miscalculation of the date of conception. Less common reasons might include being pregnant with twins or multiples (extra bundles of joy!) or a potential miscarriage, ectopic, or molar pregnancy (all of which are bad things). If you're in the healthy range, even if you're near the upper or lower extremes, and you don't have any symptoms of complications, then odds are you're doing just fine, and for whatever reason you're an outlier—probably just mathematical error.
Another thing which you need to know about HCG levels is that in 85 percent of pregnancies, levels double every two to three days. The rate of increase is important—if it's not steady or if the HCG levels are actually declining, it could mean that something is wrong with the pregnancy. If there is anything genuinely alarming, your doctor will order additional tests for you (usually an ultrasound) in order to figure out what (if anything) is going on. Usually there is nothing to worry about—most pregnancies go smoothly.