6 Week Ultrasound

During pregnancy there is a line of doctor’s examinations and tests. With the coming of new techniques, scanning and imaging is improving over time. 6 week ultrasound is crucial as this is the first time when the doctor can hear the heartbeat and see a clear picture of developing fetus.

There are many tests that can determine whether the fetus is growing normally but most of them are invasive. However, in case the doctor needs to get a clearer picture then he may use a vaginal ultrasound instead of the normal 6 week ultrasound over the belly.

During ultrasound a hand device is either placed on your belly or taken into the vagina. The sound waves emitted from this help form a clear image of the fetus. Ultrasound also helps to determine sex of child, due date, and any other abnormalities if present.

What happens when you’re 6 weeks pregnant?

At such an early stage your fetus is barely visible and organs cannot be distinguished very well. Nevertheless it is visible in the 6 week ultrasound.

6 Week Ultrasound
6 Week Ultrasound

Earlier the first ultrasound used to after 7 weeks pregnancy and more commonly 8 weeks ultrasound. But now it is possible to get an ultrasound at 6 weeks pregnant stage. The symptoms of pregnancy at this stage are distinct and no doubt remains as about one and half month is past conception.

6 weeks pregnant is one month and week after conception. You may not discover the exact time you got pregnant because missed period is a common sign of pregnancy. However, conception takes place two weeks before the period’s due date.

Gynecologists consider gestational age from the day of conception and not from missed period. Therefore they add about two weeks to the time you measure, unless you already know what they know!

What is size of baby at 6 weeks?

The baby is hardly the size of pea and is rapidly growing. The earlier stages of pregnancy see a rapid growth of the fetus and later it is the development which is a priority.

The baby is quarter of an inch and will be half an inch by the 7th week of pregnancy.

Your baby’s heart starts beating at rate of 150 times a minute. The mother’s body has high levels of progesterone that make the uterus wall thick which is another visible change in 6 week ultrasound.

The thickness of uterus lining also determines whether a woman is pregnant. A certain thickness of endometrium is essential for sustaining the baby.

How does a 6 weeks pregnant belly look like?

The 6 weeks pregnant belly isn’t much noticeable. If you see any significant baby bump then it’s probably bloating. The rising levels of progesterone hormone, the main pregnancy hormone, cause bloating. T

he digestive system is no longer as efficient and so 6 weeks pregnant symptoms like constipation occur. In case of twins the growth rate is rapid and so you will have a baby bump sooner. But for 6 weeks pregnant belly you’ll hardly have any observable changes.

6 weeks Ultrasound

There is no significant thing that you’d be able to recognize in a 6 week ultrasound. Your doctor will be probably ask you to wait before getting your first ultrasound scan until 8th or 9th week.

In case you’ve any major risk during pregnancy then your doctor may recommend an early ultrasound. Nevertheless, your first prenatal checkup will happen right away when you confirm that you are pregnant.

What all can you see in 6 week pregnant ultrasound?

6 things you can see in 6 week ultrasound:

  1. Baby pole: At such an early stage it is difficult to see any prominent features of the baby. Your baby will only be visible as a fetal pole. This is a curved structure with a tail at one end and thickened head at another. The measurement used for it is the crown to rump length. When this ratio is more than 5, which happens to by 6 week then you hear fetal heartbeat.
  2. Gestational sacs: In case you are carrying twins they develop later than a singlet. So you’ll also be able to make out whether you’ve two gestational sacs. In that case you will be expecting twins. Chorionic sac has the fluid that’ll fill the uterus and provide buoyancy and transport medium. Yolk sac is responsible for the early nutrition of the embryo until the blood connection develops across the placenta. Even if fetal pole is not clearly visible due to slower early development, it doesn’t mean that you had miscarriage.
  3. Position of pregnancy: Some women have a low lying placenta that poses a lot of problem if found at later stage. This is also the stage when the doctor will be able to warn you about any such placenta problems. The doctor can figure out the direction of attachment and growth of the fetus.
  4. Enlarged uterus: The increase in thickness of wall of uterus is one of the rare ways of diagnosing pregnancy. When the uterine wall thickening is more than 9mm it is appropriate for sustaining pregnancy. For women with endometrial lining below 6mm, supplements are prescribed. This is another observable thing in a 6 week ultrasound.
  5. Hear heartbeat: Once the fetal pole is visible, it is possible to hear baby’s heartbeat. Doctor will be able to precisely hear it. You’ll also hear it, if it is clearly detectable. At this age the heartbeat is from 90-110. If heartbeat is not detected then the doctor will advise you to come for a second ultrasound. Unless there is no detectable heartbeat at 7 week ultrasound, there is no reason to worry.
  6. Direction of flow of blood: The ultrasound scan also shows the direction of blood flow. This also helps in identifying the exact location of pregnancy. Ectopic pregnancy and other abnormalities will cause a blood flow pattern directed to other places. These pregnancy complications need to be detected and treated. At later stages, these can even interfere with the female’s fertility.
  7. 6 weeks pregnant symptoms: Now that one and a half month is past conception, all the confusion subsides. If you are carrying it will be evident through symptoms. There is no longer possibility of having any 6 weeks pregnancy symptoms which are not because of pregnancy.

Most common 6 weeks pregnant symptoms are:

  1. Morning sickness
  2. Bloating
  3. Fatigue
  4. Sore breasts
  5. Hormonal fluctuations
  6. Uneasiness of uterus
  7. Flaccid muscles
  8. Salivation
  9. Dizziness or low blood pressure during pregnancy
  10. Brown discharge

How does a 6 weeks pregnant fetus looks like?

The baby is just as big as a sweet pea but the internal organ development is progressing. At 6 weeks pregnant the nervous system of the fetus develops. Blood circulation is rapid and baby starts moving its webbed hands.

By the end of 6th week the fingers start forming. There is formation of facial features such as nose, lips depression, eye pits and ear marks.

Now the baby gradually starts responding to external stimuli. There is organ formation and intestine has loops.

Spleen, bone marrow cartilage and lungs start forming. The digestive tract above the intestine including stomach and esophagus is also present developed in varied extent.

No fetal pole, empty sac or no fetal heartbeat?

There can be many reasons for not being able to see anything in a six weeks ultrasound. It doesn’t necessarily mean that you had a miscarriage or were not pregnant.

Here are 3 major reasons for nothing in 6 week Ultrasound:

  1. Miscalculation: It is not simple to calculate your pregnancy date by yourself. Doctors consider pregnancy two weeks before missed period date. The due date of period rarely is like a monthly anniversary. It keeps fluctuating a bit. In case of women with irregular period, finding gestational age is even difficult. If there is a miscalculation and your pregnancy is not yet 6 weeks, you cannot even detect the miscalculation. So in this case it is totally normal to have an unsuccessful ultrasound. Beta hCG levels during pregnancy differ in increment pace for different women.
  2. Slower development: Some fetuses may not be on a linear curve of development. The can take longer to grow and cross developmental milestones at early stage and later pace up. In that case it is normal to not hear fetal heartbeat. Other reason for slow development can be malnutrition and hormonal imbalance.
  3. Pregnancy abnormalities: It is unnerving when you detect pregnancy abnormalities after being told that you are pregnant. You shouldn’t bottle up emotions as they can have devastating effects of long term anxiety disorder or depression. Ectopic pregnancy, tubal pregnancy or even miscarriage is a possibility in every pregnancy. Every pregnancy has a risk of development defect. Ultrasound is the most conclusive way of detecting such defects.

It is best to get an early ultrasound for this reason. Treating these conditions is not possible at later stages.


  1. I Ovulated three days back and I slept with my husband for 5days ,now am experiencing rise in temperature… Have I conceived?

    • Just three days after conception very few advanced tests can detect pregnancy. You must wait for two weeks and take a pregnancy test. Read about triphasic pattern of BBT after implantation.


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