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Pregnancy of unknown location (PUL)

Patient information A-Z


As a result of symptoms early in your pregnancy (most commonly bleeding and/or abdominal pain) we have performed an ultrasound scan.

During the ultrasound scan you have been told that no pregnancy was seen in your uterus (womb) despite a positive urine pregnancy test and so your condition has been given the label ‘Pregnancy of Unknown Location’. This is a confusing comment. We hope that this leaflet helps to try and explain what we mean and what happens next.

A pregnancy of unknown location means one of three possibilities (further details of each possibility is given later in this leaflet):

  1. Very early intrauterine pregnancy – this means the pregnancy is in the correct place but too small to see on scan
  2. Miscarriage – this means the pregnancy has ended and the developing tissue has already passed out of the body
  3. Ectopic pregnancy – this means the pregnancy is developing outside the uterus.


Studies report that 5–42% of women attending for an ultrasound assessment in early pregnancy will be classified as having a PUL. However reports from specialized early pregnancy units describe lower PUL rates of 8–10%.

The next step

At the moment we cannot be sure which of the above three possibilities applies to you.

Details of your symptoms and past gynaecological history can help us to decide what is most likely and a member of staff will discuss this with you.

If the risk of an ectopic pregnancy is high, we will suggest you come into hospital and be monitored in case you have any internal bleeding. Factors that make you high risk are:

  • Previous ectopic pregnancy
  • Pelvic inflammatory disease (PID)
  • Previous tubal surgery
  • Smoking
  • Appendicitis
  • Presence of a coil (IUCD)
  • Use of the mini pill (POP)
  • In Vitro Fertilisation (IVF) or ovulation induction

If you do not have any risk factors, we will take blood samples and allow you to leave. These blood samples test the level of your pregnancy hormone (beta hCG). The pattern of change of the hormone level over the next few days will show whether you have an early developing pregnancy, a miscarriage or an ectopic pregnancy. You will be asked to return in 48 hours for more blood samples. Please attend Clinic 24, where the blood samples will be taken.

When you return for the blood samples, and we have concerns, we will suggest you stay in hospital until a further decision is made on your treatment. If we do not have concerns, you will be allowed to leave. You will usually be contacted later the same day with information about your result, what this means and what is next.

What to do if you have concerns regarding your symptoms

If you experience any new symptoms or if existing symptoms worsen, telephone either clinic 24 or Daphne Ward for advice (see contact numbers later in this leaflet). If your symptoms require urgent medical attention, attend the emergency department for assessment.

Symptoms to be aware of:

  • Abdominal or pelvic (lower part of the abdomen located between your hip bones) pain
  • Pain on the top of your shoulders
  • Vomiting and/or diarrhoea
  • Dizziness, fainting, pale face
  • Pain on passing stool/urine, backache, shivering, breast tenderness

We understand that changing/ worsening symptoms can be frightening. Please do not hesitate to contact us if you are unsure what to do.

Some more detailed information about each of the three possible conditions is explained here:

Early Intrauterine Pregnancy (30-47%)

This is where the pregnancy is developing inside the uterus. However, it has not yet developed to a stage where we can see it on ultrasound scan. It is not possible to tell whether this pregnancy is viable (that is, whether it will continue to develop normally). This is a very common situation especially if you are unsure of the date of your last period and/or have irregular periods.

If the blood samples suggest an early pregnancy, we will invite you for a repeat scan. We schedule this for 7-14 days after your first scan, to allow time for the pregnancy to develop. At this time, we should see the pregnancy in the uterus, assuming you have had no further heavy bleeding.

Miscarriage (50 – 70%)

If you have had heavy bleeding in this pregnancy it is quite likely you may have passed the pregnancy during this time. As everything has passed and nothing is seen in your uterus on scan we term this a complete miscarriage.

If the blood samples suggest a complete miscarriage, no further intervention is needed, just a follow up telephone call from us in two weeks to check your symptoms. We would ask you perform your own home urinary pregnancy test at this point to confirm you are no longer pregnant, confirming the diagnosis of a miscarriage.

You will then be discharged to your GP. You can, if appropriate and you feel ready, try to conceive again once your periods restart, this can be in two to six weeks.

Ectopic Pregnancy (6 – 20%)

Ectopic pregnancy is a common, potentially life–threatening, condition affecting one in 100 pregnancies. It occurs when the fertilised egg implants outside the cavity of the uterus, usually in the fallopian tube and as the pregnancy continues it causes pain and/or bleeding. If it is not treated quickly enough, the fallopian tube can burst causing internal bleeding. This can lead to shock and even death.

If you do have an ectopic pregnancy this will be treated either with medication or surgery or sometimes close monitoring. Further information will be given to you about this if it applies to you.

Persistent PUL

A very small proportion of women with a PUL may be given the descriptive term of ‘persisting PUL’. In such cases the beta hCG level does not spontaneously decline but plateaus, whilst no intrauterine or ectopic pregnancy can be identified on follow-up scan. This is likely to be a small ectopic pregnancy that has not been visualized or some retained tissue in the uterus.

This can be treated with either close monitoring or medication. You will be given further information should this apply to you.

Contacts and further information

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

If you feel that you, or your partner, need more information at any time then please use the contact numbers below:

Clinic 24 (early pregnancy unit and emergency gynaecology unit)
01223 217636
Monday to Friday 0800 until 2000
Saturday and Sunday 08.30 – 14.00 (telephone calls only)
Closed Bank holidays

Daphne ward (inpatient gynaecology)
01223 257206 All other times

You can also attend the emergency department (ED) at any time if you are concerned about the amount of pain or any of the symptoms listed above in the “when to seek medical advice” section and Clinic 24 is closed or you are unable to contact your GP.

When to seek advice/ help

You should seek medical advice from your GP, clinic 24, Daphne ward or the emergency department (overnight) for:

  • You experience any increase in pain
  • Pain somewhere you have not previously felt it such as you calf or chest
  • Shoulder-tip pain
  • Paracetamol and or Ibuprofen (Nurofen) is insufficient for any pain you are experiencing
  • You feel faint or dizzy
  • Smelly vaginal discharge
  • Raised temperature (fever) and ‘flu-like’ symptoms
  • Excessive bleeding (requiring you to change a sanitary pad every half an hour)

Further support

Privacy and dignity

Same sex bays and bathrooms are offered in all wards except critical care and theatre recovery areas where the use of high-tech equipment and/or specialist one to one care is required.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151