This leaflet answers common questions about pregnancies of unknown location. If you would like further information, or have any worries, please do not hesitate to ask your nurse or doctor. In all cases, a specialist member of staff will explain more about the condition to you and answer any questions you may have.

What is a pregnancy of unknown location?

This is when you have a positive pregnancy test, but it has not been possible to see your pregnancy on the ultrasound scan. There are three possible reasons for this:

The pregnancy is too early to see on a scan

Home pregnancy testing kits are now extremely sensitive and can sometimes detect the pregnancy hormone just nine days after conception (23 days from your last period). However, a pregnancy may not be seen on ultrasound until around three weeks after conception (five weeks from your last period). Sometimes women attend the early pregnancy unit with a pregnancy that is too early for us to see. 

An early miscarriage has occurred

If you have had heavy bleeding, it could be that an early miscarriage has occurred.

The pregnancy is developing outside the womb

This is known as an ectopic pregnancy and the most common location is in the fallopian tubes. An ectopic pregnancy is the least likely possibility but, if ignored, can be life threatening. We cannot exclude an ectopic pregnancy until we can see a pregnancy inside the womb, or your hormone levels have significantly decreased.

What happens next?

To help us determine if and where your pregnancy is developing, we need to look at your pregnancy hormone level and how it changes over 48 hours. After your scan, you will have a blood test to measure two hormones – human chorionic gonadotrophin (hCG) and progesterone. In most cases you will need to return after 48 hours for a repeat test so that we have two levels to compare.

After your second blood test, one of our nurses should call you to discuss the next steps. If you don’t hear from us by 5pm on the day after your second test, please contact the unit directly. Our numbers are at the end of this leaflet.

What happens if my hormone level is increasing?

You will be asked to return for a repeat pelvic ultrasound scan once we expect to be able to see your pregnancy on the scan.

What happens if my hormone level is decreasing?

You will either be asked to come back for a further blood test or asked to repeat a urine pregnancy test to check that your pregnancy hormone reading has returned to the non-pregnant level.

Things to watch out for

If you develop any of the following symptoms, contact us immediately or attend your local emergency department for clinical assessment:

  • Severe abdominal pain.
  • Pain on the tip of your shoulder.
  • Dizziness or feeling faint.
  • Significant vaginal bleeding.

It is important to take a copy of your latest ultrasound scan report with you.