An early pregnancy ultrasound scan is a way of checking that the baby is growing in the correct place (in the womb), the number of babies (are you having 1 or twins/multiples), whether the baby is alive (we can see a heartbeat) and to accurately date the pregnancy.
Your Baby at 7 Weeks Pregnant
During the seventh week of pregnancy, your baby’s growth is still happening rapidly, now measuring over 10,000 times larger than when it first implanted in your uterus—approximately the size of a blueberry.
This week, crucial parts of the eye responsible for vision, such as the cornea, iris, pupil, lens, and retina, begin to form. Additionally, essential organs like the liver, esophagus, stomach, and pancreas are also in the early stages of development.
The umbilical cord, connecting your baby to the placenta and providing oxygen, nutrients, and waste removal, is actively developing at 7 weeks pregnant.
Webbed hands and feet stubs have emerged as your baby’s limbs take shape, and soon little fingers and toes will become more defined.
Formation of the baby’s mouth, tongue, and kidneys is underway, and it won’t be much longer until your baby starts producing urine.
At this stage, a significant focus of your baby’s development is on the head, particularly the brain. About 100 new brain cells are forming every minute, contributing to the ongoing development of the brain and spinal cord at 7 weeks pregnant.
You at 7 Weeks Pregnant
Around the 7-week mark of pregnancy, you might begin to notice heightened symptoms like morning sickness, tender breasts, and aversions to certain foods.
By this time, it’s recommended to have already started taking prenatal vitamins, particularly 400 micrograms of folic acid daily until your second trimester.
Additionally, a daily intake of around 10 micrograms of vitamin D is advised throughout your pregnancy.
Whether or not you’ve had a positive pregnancy test, many women typically experience some early pregnancy symptoms by this point, with nausea or morning sickness often being one of the more challenging aspects. However, it’s entirely normal not to have any pregnancy symptoms at this stage as well.
What NHS Scans Will I Routinely Have?
Most NHS trusts offer two routine scans.
You will be offered a scan between 11-14 weeks (or between the end of the first trimester and early second trimester) and another scan between 18-22 weeks (or in the second trimester).
11-14 Week Ultrasound
The ultrasound scan performed between the 11th and 14th week is commonly referred to as a dating scan. This scan is instrumental in determining the precise number of weeks into your pregnancy and providing an estimated due date.
Related: 14 week ultrasound
18-22 Week Ultrasound
The scan conducted during the 18-22 week period, which falls within the second trimester, is alternatively called the Fetal Anomaly Scan or Mid-Pregnancy Scan.
Its primary aim is to assess your baby’s well-being and development, ensuring that everything appears normal.
What to expect at your 7 week ultrasound scan
At about 7 weeks past the first day of your last menstrual period (if you have a 28-day menstrual cycle) quite often the ultrasound will be performed transabdominally (tummy scan).
How do I Prepare for a Seven week ultrasound?
For this type of scan, you will require a full urinary bladder, so you will be asked to drink approximately 1-2 pints of water an hour before your scan.
What can I expect during the transabdominal ultrasound scan?
When laying on the scan couch you will be asked to lower your clothes to your bikini line (yes your womb is that low down) and a piece of paper will be placed into your clothing to attempt to keep the gel off them. The Sonographer will then put some gel on your tummy and place the probe onto the skin surface.
When might a transvaginal scan be needed?
Sometimes the Sonographer will not get a clear view doing the tummy scan (this can be for various reasons including the shape of the womb, size of pregnancy, how much water is in your bladder, size of Mum, fibroids etc), and will offer a transvaginal ultrasound (internal scan).
You will be asked to empty your bladder prior to this scan, and then remove your lower clothing. Your dignity should be maintained at all times (you should be covered).
What can I expect during a transvaginal ultrasound scan?
Internal scans are usually performed with patients lying down and knees bent, but you could be scanned with legs in stirrups or even sitting.
The probe is cleaned and sterile gel plus a sheath/cover are applied. The probe should be gently inserted into your vagina – this should not hurt. Remember the scan is only performed with your consent, if you are in discomfort please let your Sonographer know and they should stop.
When performing transvaginal scans the ultrasound image is formed by a higher frequency of sound which means that smaller objects can be visualized.
Will my baby have a heartbeat at the 7-week ultrasound?
If your baby measures 7mm (approx 6 weeks & 4 days) or more head to bum (CRL) then they should have a heartbeat. If there is no heartbeat unfortunately this means your baby has died -this is called a missed miscarriage and you may require some medicine to help you pass your pregnancy.
If your baby measures less than 7mm and baby’s heartbeat cannot be detected this is called a pregnancy of uncertain viability and you should be invited back for a follow-up ultrasound. It may be that you are too early for us to see.
What will I see at the 7-week ultrasound?
At 7 weeks you should hopefully see a pregnancy sac in the womb (this will look like a black hole in the womb). Within this there sound be a small round circle (the yolk sac) and next to this a small bright structure (your baby) with what appears to be a pixel flickering in the middle (their heartbeat)
Would you be able to see an ectopic pregnancy at 7 weeks?
Most ectopic pregnancies (pregnancies outside your womb) can be seen at a gestational age of 7 weeks. These would sometimes be seen as a live baby in the wrong place, but more common is a “doughnut-like” mass and some fluid within the pelvis.
Ectopic pregnancies are emergency conditions but do not necessarily mean surgery (some are treated with medicines).
Ectopic pregnancy symptoms include:
- Not getting your period and signs of being pregnant.
- Pain in your tummy on one side, down low.
- Bleeding from your vagina or brown watery discharge.
- Feeling pain at the top of your shoulder.
- Discomfort when you pee or poop.
Sometimes the Sonographer can not visualize a pregnancy either inside or outside the womb. This is called a pregnancy of an unknown location. In this case, you should be scheduled for a follow-up scan. It may be that you are too early for us to see…If you are attending an early pregnancy unit, blood tests may be performed at 48-hour intervals to see whether your hormones are doubling.
Related: 7 weeks pregnant symptoms
Can you see twins at 7 weeks?
Yes, we can see twins at 7 weeks, and we should be able to tell you the type of twins they are. If they are non-identical (Diachorionic) there will be 2 separate pregnancy sacs whilst for identical twins (Monochorionic) there will be 1 sac containing 2 babies.
There is a very rare condition called a hypertrophic pregnancy which is where 1 twin is in the womb and the other is ectopic (outside the womb). If this condition is diagnosed it usually requires surgery to remove the ectopic twin.
No fetal pole at 7 weeks / empty sac, what does this mean?
If your pregnancy sac measures 25mm or more then it should contain a small embryonic pole/baby. If there is no baby unfortunately this means your baby will not develop -this is called a missed miscarriage and you may require some medicine to help you pass your pregnancy.
If your pregnancy sac measures less than 25mm and has no baby this is called a pregnancy of uncertain viability and you should be invited back for a follow-up ultrasound. It may be that you are too early for us to see.
Can I find out my baby’s gender at 7 weeks?
It is impossible to find out on ultrasound the gender of your baby at 7 weeks. However, there are blood tests available that will be able to give you this information if you can not wait.
A mum of two beautiful daughters and state registered Radiographer who has specialised in ultrasound. She attended Liverpool University for both undergraduate and postgraduate studies.
Since qualification in ultrasound in 1999 Gillian has acquired a vast array of experience in both the NHS and Private sectors.
A dedicated professional who has regularly lectured on and has been an external examiner on the MSc Ultrasound courses at Liverpool University and St.Martin’s college, Lancaster.
Gillian is currently on the Society of Radiographers Expert Witness list for her knowledge of obstetric ultrasound.
Gillian is recently received MAMA Academy “Healthcare Professional of the Year 2023 Award”