The developmental phase of a baby starts the moment sperm fertilizes the egg. It is important to know that the early phase of your baby's development will ensure healthy pregnancy and delivery. One simple way to check the health of a fetus is through vaginal ultrasound that detects a fetal heartbeat. A fetal heartbeat will be detectable usually as early as 6 weeks. But, if there is no heartbeat at 6 weeks, it can be normal since usually, the heartbeat of baby will be detectable at 8 weeks.
No Heartbeat at 6 Weeks: Is It Normal?
If you are six weeks pregnant and your doctor couldn't see or hear a heartbeat on ultrasound, it could be normal, since we have known the fetal heartbeat usualy can be heard around 8 weeks with an ultrasound exam. If you want to detect the heartbeat with a Doppler exam, it will be around 10 week as early, and usually you can heart obvious fetal heartbeat at 12 weeks.
However, sometimes, no heartbeat at 6 weeks could also be due to a miscarriage, ectopic pregnancy, or equipment errors. After noticing no heartbeat at 6 weeks and if you are worried a lot about the condition, your doctor will ask for a lab test to know your human Chorionic Ganadotropin (hCG) levels. He/she is likely to ask for a repeat ultrasound within the next week to rule out possible errors.
Why Check hCG Level?
Your body produces hCG only when you're pregnant. When you conduct a pregnancy test at home, the kits look for the presence of this hCG hormone in your urine. It is produced after the implantation of fertilized egg in the uterus. Your doctor can detect pregnancy 8-10 days after fertilization by conducting an hCG test, and if the level is above 5, it usually means you're pregnant. However, you have to wait until 14 days for home pregnancy tests to show correct results. The rate of hCG will double in every couple of days. When there is no heartbeat at 6 weeks, your doctor will check for hCG to confirm if you're still pregnant.
Here is the normal range of this hormone during different weeks of pregnancy to help you understand the result.
Weeks from Last Missed Period |
Amount of hCG in mIU/ml (milli-international units per milliliter) |
3 |
0-5 |
4 |
5-426 |
5 |
18-7,340 |
6 |
1,080-56,500 |
7-8 |
7,650-229,000 |
9-12 |
25,700-288,000 |
13-16 |
3,300-253,000 |
17-24 |
4,060-165,400 |
25-term |
3,640-117,000 |
Postpartum |
Below 5; non-pregnant level |
What Should a Normal Fetal Heartbeat Be Like?
When there is no heartbeat at 6 week, it is obvious to worry about fetal health. However, when there is a heartbeat, it is important to ensure that it is normal. A normal fetal heart rate (FHR) is measured in beats per minute (BPM) and is usually between 120 and 160 bpm. You can measure it sonographically during 6 weeks. It is important to bear in mind that the normal FHR range will keep changing during gestation – it reaches around 170 bpm at 10 weeks and decreases again to 130 bpm at term.
Even though the myocardium begins to contract in a rhythmic fashion around 3 weeks, it usually shows on sonography only around 6 weeks of pregnancy. Here's more about the FHR during different stages of pregnancy.
Weeks |
Beats Per Minute |
5-6 |
110 |
9-10 |
170 |
14 |
150 |
20 |
140 |
By term |
130 |
How to Keep a Healthy Fetal Heart
There can be so many reasons why there is no heartbeat at 6 weeks, and most of these reasons are beyond your control, because it is usually caused by genetic or chromosomal abnormalities. You can, however, take certain steps to ensure a healthy fetal heart.
- You should take folic acid before and during your pregnancy to prevent congenital heart disease in your baby.
- You should quit smoking if you're pregnant because maternal smoking, especially during the first trimester, is the reason of baby's heart defects in 2% of cases.
- You should work with your healthcare provider to keep your blood sugar under control if you have already developed gestational diabetes.
- Don't use Accutane for acne because it can also lead to certain fetal heart defects.
- Don't use alcohol or other recreational drugs when you're pregnant.
It is important to understand that even if you take all precautionary measures and do exactly as your healthcare provider says, you may still fail to prevent a congenital heart defect in your baby. Just understand that this is not your fault because several factors are always out of your control. The good thing is that early detection will help select the best treatment option for your baby to live a healthy life.