Low HCG Levels in Early Pregnancy: What to Know

Question
Hi my name is Laura. My husband and I got pregnant for the 1st time a few weeks back. We are thrilled! According to my doctors, I am almost 6 weeks along (my last period was 2/22/08). However yesterday, I started spotting just a little bit (brownish in color)and so I went in to the doctor. They did a vaginal ultrasound and couldn't see anything in my uterus yet. They also sent me to get blood work done to check my HCG level. I got the results today and my number had increased from 41 on (3-20-08) to 600 on (4-4-08). However, they are concerned that it is NOT high enough and are doing another blood test on Monday. I'm terrified. I feel great. The spotting has stopped. I have normal pregnancy symptoms (especially breast tenderness & fatigue). No cramping or backaches. My question is, how common is to for an HCG level to be at 600 at almost 6 weeks? Should I be this concerned?

Answer
Dear Laura,

The average hCG level at 6 weeks of pregnancy is 1,080 - 56,500 mIU/ml. So, your level of 600 mIU/ml would be pretty low. In the 1st trimester of a healthy pregnancy, we expect hCG levels to double every 48-72 hours. If your level on 3/20 was 41, it should have been over 5000 by 4/3 if it were doubling appropriately. Also, by 6 weeks gestation, they definitely should have noted evidence of the pregnancy within your uterus. At 4.5 weeks, they can typically visualize a gestational sac within the uterus. Did they check for an ectopic (tubal) pregnancy?

An ectopic pregnancy occurs when the fertilized egg attaches itself in a place other than inside the uterus. Almost all ectopic pregnancies occur in a fallopian tube - thus, sometimes called tubal pregnancies. An ectopic pregnancy happens in 1 out of 60 pregnancies.

Ectopic pregnancies are diagnosed by your doctor, who will probably first perform a pelvic exam to locate pain, tenderness or a mass in the abdomen and usually will also use an ultrasound to determine whether the uterus contains a developing fetus. The hCG level is also important. An hCG level that is lower than what would be expected is one reason to suspect an ectopic pregnancy. Low levels of progesterone may also indicate that a pregnancy is abnormal.

Symptoms of an ectopic pregnancy would include:
- Vaginal bleeding, heavier or lighter than your normal period
- Gastrointestinal symptoms
- Weakness, dizziness, or fainting
- Sharp or stabbing pain that may come and go and vary in intensity. The pain may be in the pelvis, abdomen or even the shoulder and neck (due to blood from a ruptured ectopic pregnancy gathering up under the diaphragm). This should be reported to your doctor right away.

I hope this has helped you and answered your question. I wish you well and will have a good thought for you.

Brenda