Early Pregnancy Scan

An early pregnancy scan is an ultrasound performed before 12 weeks of gestation. It helps confirm the pregnancy and can identify potential concerns as early as possible.

Reasons for an Early Pregnancy scan

• Dating (irregular menstrual cycle or unknown last period)
• ​There is a history of previous miscarriage
• There is a history of ectopic pregnancy
• Bleeding or pain in early pregnancy
• Excessive nausea (hyperemesis)
• ​Suboptimal or excessive BHCG (pregnancy hormone) levels

Benefits of an Early Pregnancy ultrasound

• Confirm a viable pregnancy and its location, with a fetal heartbeat typically visible from around 6 weeks
• ​Help rule out an ectopic pregnancy
• Assess gestational age and due dates
  
• Identify ovarian cysts or uterine fibroids
  

How is an Early Pregnancy scan performed?

• Around 8 weeks of pregnancy, the embryo can often be seen clearly using a transabdominal scan, which assesses the lower abdomen with a full bladder.
  
• If performed earlier than 8 weeks, or if the embryo isn’t clearly visible, a transvaginal scan may be used to achieve optimal visualisation.
  

When is the scan performed?

The timing of a transvaginal scan depends on the reason for the scan. Patients experiencing pain or bleeding will be seen urgently. If reassurance is needed, a scan at 7 to 8 weeks of gestation is ideal, as it provides more information about the pregnancy.

How accurate is Early Pregnancy dating?

​Pregnancy dating is most accurate between 7 and 11 weeks of gestation. Measuring the embryo’s crown-rump length at this stage provides an estimate of gestational age accurate to within about 3 days.

What can the scan show?

• 5 weeks - a pregnancy sac may be visible
• 6 weeks - the embryo can usually be seen
• The fetal heartbeat is usually visible when the embryo measures around 4 mm, typically at about 6 weeks of gestation.