What Do You See At A 5 Week Early Pregnancy Scan And Why Should I Wait Until 7 Weeks?

During a pregnancy scan at 5 weeks, the structures are still very small, often making it challenging to discern much detail through ultrasound. Even by 6 weeks, visualising the embryo can be difficult for some individuals. It’s certainly worth waiting until 7 weeks if you want to see more of your baby in the scan.

5 Week Pregnancy Scan

In the provided images, Baby Scan Ashford will illustrate a pregnancy at 5 weeks or more, though clarity may vary among individuals. At this stage, without being able to precisely measure the embryo, we typically rely on assessing the mean sac diameter, which involves three measurements of the sac to estimate a due date. However, this method isn't as precise as measuring the embryo itself.

What can typically be seen is a dark area representing the gestation sac, with a small white circle inside known as the yolk sac. The yolk sac functions to provide nutrients to the developing embryo until the placenta assumes this role later in pregnancy. The presence of only a yolk sac allows us to confirm whether the pregnancy is correctly situated or potentially ectopic.

6 Week Pregnancy Scan

Moving to a 6-week pregnancy, it becomes feasible to visualise the embryo more clearly and accurately measure the gestational age. However, detecting a heartbeat at this stage isn't always guaranteed.

The absence of a visible heartbeat during this period can lead to anxiety, prompting the need for a follow-up scan in a week or so. To mitigate this uncertainty, at Baby Scan Ashford, we typically recommend early pregnancy scans starting from 7 weeks.

7 Week Pregnancy Scan

At 7 weeks, the embryo measures approximately 10mm from head to bottom or crown to rump. While the yolk sac might not be visible in all cases, it's usually possible to detect a heartbeat at this stage.

This is why we advocate for early pregnancy scans around this time, as it can alleviate the stress of potential uncertainties and reduce the need for additional appointments.

To summarise the precise differences between 5,6 and 7 weeks of pregnancy scans:

5 Weeks Pregnant:

• Gestational Sac -  At 5 weeks, a small gestational sac may be visible. This is the first structure that can typically be identified on an ultrasound
  • Yolk Sac - A yolk sac may also be seen within the gestational sac. This sac provides nourishment to the developing embryo until the placenta forms
  • Foetal Pole - In some cases, a tiny Foetal pole may be visible. This is the early stage of the embryo, which will eventually develop into the foetus

6 Weeks Pregnant:

• Foetal Heartbeat - At 6 weeks, a Foetal heartbeat may become visible on the ultrasound. This is a significant milestone in pregnancy confirmation and is reassuring for the viability of the pregnancy
  • Embryo Development - The embryo may become more defined, and limb buds may start to form. However, it's important to note that development can vary between pregnancies

7 Weeks Pregnant:

• Embryonic Development - By 7 weeks, the embryo continues to develop rapidly. Limb buds may become more distinct, and features such as the head and body may become recognisable
  • Improved Visualisation - As the pregnancy progresses, the structures within the gestational sac become clearer, allowing for better visualisation of the foetus and surrounding structures

Natural Variations

However, it's essential to acknowledge the variability in menstrual cycle lengths, which are typically estimated at 28 days but can range from 21 to 35 days. Consequently, if your cycle is longer or shorter, you may be slightly less or further along in your pregnancy. By aiming for a 7-week scan, we increase the likelihood of capturing all necessary information in one appointment, despite the anticipation felt by many due to the early detection capabilities of today's pregnancy tests.

Safeguards

It's crucial to note that if you experience bleeding or pain, it's essential to rule out the possibility of an ectopic pregnancy. In such cases, a visit to the early pregnancy assessment unit may be necessary, where they can conduct further scans and quantitative Beta hCG measurements to gather additional information. Nonetheless, sometimes a watchful waiting approach might be deemed appropriate. Further details on ectopic pregnancy will be provided later. If you have any questions about any of our scan packages then just get in touch.