Pregnancy of unknown location

What is a ‘pregnancy of unknown location’?

A ‘pregnancy of unknown location’ (PUL) describes a pregnancy where you have a positive pregnancy test but on ultrasound scan there is no sign of a pregnancy inside your womb (uterus) or any additional features to suggest it could be developing outside the womb.

These are the possible reasons to explain why a pregnancy was not seen when you were scanned:

• You have had a miscarriage/your pregnancy is not developing – The pregnancy may have ended and the developing pregnancy tissue has either been reabsorbed by the body or passed out of the body. This happens in about 71% of our patients.
• You have an early intrauterine (inside the womb) pregnancy – The pregnancy may be in the womb but is too small and too early to detect on an ultrasound scan. It may also be harder to see a very early pregnancy inside the womb if you are overweight or obese or if you have fibroids in your womb. This happens in about 14% of our patients.
• You have an ectopic pregnancy – The pregnancy may be developing outside the womb. This happens in about 9% of our patients.

Early normal pregnancy

This is where a pregnancy is developing inside the womb but it is not yet big enough to be seen on an ultrasound scan. This indicates that the pregnancy is less than 5-6 weeks old. This is quite a common situation if:

• You are unsure of the date of your last period.
• You have irregular periods.
• Your last period was less than six weeks before the scan was performed.

If, after some blood tests, it appears that you have a very early intrauterine pregnancy, you may be offered a further scan in 7-14 days’ time to see if a pregnancy is developing in your womb.

Miscarriage / Pregnancy is not developing

A miscarriage may have occurred where you have experienced bleeding and passed all of the pregnancy tissue before your scan. If this is the case then nothing will be seen in your womb on scan. Sometimes a pregnancy can stop developing at a stage that is so early that it is not visible on an ultrasound scan.

If, after some blood tests, 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 three weeks’ time. If the repeat test is positive, you should contact the Gynaecology Acute Treatment Unit (GATU) for further advice.

If the repeat test is negative, you should wait for your next period before trying to conceive again. Please be aware that you can ovulate (and fall pregnant) as early as ten days after your pregnancy loss. Your GP or family planning clinic can offer you contraception advice.

Ectopic pregnancy

An ectopic pregnancy is a pregnancy that develops outside the cavity of the womb, usually in the fallopian tube. It is not a pregnancy that can successfully continue and requires careful management. If left unmanaged, it can cause severe internal bleeding if it ruptures (bursts) leading to significant harm to your health and in very rare cases, death.

It can be difficult to diagnose an ectopic pregnancy but a combination of listening to your symptoms, examining you and doing tests can point towards the diagnosis.

If, after your tests, it appears that you have an ectopic pregnancy, it may be treated expectantly (‘watch and wait’) or with medicine or surgery depending on your specific circumstances. More information can be found in the information leaflet called Ectopic Pregnancy.

How do I find out what is happening to my pregnancy?

The doctors and nurses caring for you are rarely able to give you an answer on what will happen to your pregnancy during your first visit if your scan has shown a pregnancy of unknown location.

Usually we can give you some indication of whether a pregnancy is developing or not within 48 hours after some blood tests although we may not be able to determine where the pregnancy is located or its final outcome.

You may find this time stressful and uncertain. Our staff will try their best to answer any questions you may have. Please feel free to contact GATU if you have any concerns.

What happens next if you have a pregnancy of unknown location?

As part of your management you will be asked questions, you may be examined and you may need further investigations.

Taking a history – You will be seen by a doctor or a nurse who will ask you questions about your usual menstrual cycle, your symptoms and your past medical history.

Examination – Depending on your symptoms you may be offered an abdominal and internal examination.

Admission into hospital or Outpatient follow-up – If you are at increased risk of having an ectopic pregnancy and you have symptoms or signs that suggest an ectopic pregnancy we may suggest you stay in hospital for monitoring in case of internal bleeding. However, in most cases you can have outpatient management (where you can go home with follow up arrangements in place).

Blood test – You will be offered a blood test to check the level of a specific pregnancy hormone (HCG). This test is repeated after 48 hours (two days). We then look at the trend between the two results as one by itself does not generally give us an answer. These levels may indicate that your pregnancy is developing or not but does not confirm where the pregnancy is.

For example, after a miscarriage the level will fall between the two tests whereas in a very early pregnancy the levels will rise. You will be contacted within 24 hours by phone with the result of each test. The findings will be explained and a plan recommended.

Ultrasound scan – You may be offered a further scan in 7 to 14 days’ time if the blood tests indicate that your pregnancy may be developing normally.

What are the symptoms to look out for?

If you have been allowed home after being seen by the doctor or nurse you will be given contact details for GATU (please see Contacts/Further Information section). If you develop any of the symptoms listed below you should contact the unit immediately and you may be advised to come into hospital for review:

• New or increasing abdominal pain (that does not settle spontaneously or with paracetamol).
• Feeling dizzy, lightheaded, fainting.
• Pain at the tip of the shoulder.
• Increased bleeding.

When you attend GATU you will be seen by the doctor or specialist nurse who will assess you. Depending on the findings of this assessment you may be reassured and discharged home, given a further follow up appointment or you may be offered medical or surgical treatment.

Informed consent

This leaflet is provided to supplement verbal information that will be given to you by your healthcare provider (Doctor/ Surgeon/ Nurse) as part of the consent process prior to your procedure. Information sharing between you and the clinician is essential to ensure that your decision to consent is fully informed.

Please ask questions if you don’t fully understand or have any concerns about what is proposed. You have a right to be involved in these decisions and should feel supported to do so. Please take the time to consider what is important to you to ensure the information you receive is specific and individualised.

Contacts / Further Information

It is not unusual to feel anxious, low in mood or tearful during this time of uncertainty. Some people can even feel angry. This is normal.

If you feel that you or your partner need more information then please contact us by phone.

Other relevant leaflets

References/ sources of evidence

• NICE clinical guideline, NG126: Ectopic Pregnancy and Miscarriage
• Leeds Teaching Hospitals NHS Trust Statistics 2018
• The Ectopic Pregnancy Trust: www.ectopic.org.uk
• The Miscarriage Association. (01924 20 0799).
  www.miscarriageassociation.org.uk
• RCOG Bleeding and Pain in Early Pregnancy:
  Bleeding and/or pain in early pregnancy | RCOG