Pregnancy of Unknown Location (PUL)

What is a ‘Pregnancy of unknown location’?

You may be informed you have a pregnancy of unknown location if you have had a positive pregnancy test, or blood test and a transvaginal ultrasound examination, and it is not possible to see an intrauterine (in the uterus/womb) pregnancy on the ultrasound scan.  

Pregnancy of unknown location is not a diagnosis and is instead a term used until the final location of the pregnancy can be identified through assessment.  

There are different possible diagnoses that can explain why a pregnancy is not seen on an ultrasound scan: 

• Early Pregnancy  
• Miscarriage / Pregnancy not developing 
• Ectopic Pregnancy  

Early Pregnancy  

It may be that your pregnancy is developing inside the uterus (womb) but is not developed to a size that can be seen on an ultrasound scan. It is usually expected to be seen at around 6 weeks gestation. This situation can occur if: 

• You have irregular periods 

• You are unsure of your last period dates 

• Your last period was less than 6 weeks before the ultrasound scan was performed  

In this case, you will be offered blood tests to track your hormone levels, known as ‘BHCG levels’. If it appears that you have a very early intrauterine pregnancy, you may be offered a follow up appointment for a further ultrasound scan in 7-14 days time to see if a pregnancy has developed in the uterus. 

Miscarriage / Pregnancy not developing 

If you have experienced bleeding and passed pregnancy tissue prior to your ultrasound, it may be that you have experienced a miscarriage and nothing will be seen in your uterus on the ultrasound scan. Pregnancy’s sometimes stop developing at an early stage and may not be visible on an ultrasound scan.  

If after assessment, it appears that you have had a miscarriage or a pregnancy that is not progressing, you will be advised to perform a pregnancy test in 3 weeks time. If this test is positive after 3 weeks, then please contact the EPAU for further advice. 

     • Early Pregnancy Assessment Unit at Bassetlaw: 01909 572307

     • Early Pregnancy Assessment Unit at Doncaster: 01302 642653

Please be aware that you can ovulate and become pregnant as early as 10 days after a miscarriage or pregnancy loss. Your GP or Tri Health can offer contraception advice:

     • Tri Health Doncaster: 01302 640040 

     • Tri Health Bassetlaw: 01909 571571

Ectopic Pregnancy  

An ectopic pregnancy is a pregnancy that happens when an egg that has been fertilised has implanted outside of the uterus. As with an early pregnancy in the uterus, it may be too early for an ectopic pregnancy to be seen on an ultrasound scan. 

You could have an ectopic pregnancy that has not been seen on an ultrasound scan due to fibroids or poor view on ultrasound.  

Please contact EPAU or attend A&E if you have a pregnancy of unknown location and you experience new or increasing abdominal/pelvic pain, shoulder tip pain or feel generally unwell. 

What happens next? 

The Doctors and Nurses are unfortunately rarely able to give a definitive answer on what will happen with your pregnancy during your first visit, if your ultrasound scan has shown a pregnancy of unknown location. We follow guidelines set out by the National Institute for Health and Care Excellence (NICE) to guide your care.  

We appreciate this can be an overwhelming and uncertain time, please ask your Doctors and/or Nurses any queries you may have. If you would like any support during this time, please contact the Early Pregnancy Nurse on 01302 642812 or dbth.epln@nhs.net and they will contact you within 7-10 days. Do not contact Early Pregnancy Nurse for urgent medical care.  

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