An pregnancy of unknown location (PUL) is when you have a positive pregnancy test but we cannot see the pregnancy on ultrasound.
What does this mean?
There are three possible reasons:
- The pregnancy is too early to see on the scan. Home pregnancy testing kits are extremely sensitive and can sometimes detect the pregnancy hormone just a few days after conception. However a pregnancy may not be seen on ultrasound until about 3 weeks after conception (at least 5 weeks from your last period). This results in women attending the Early Pregnancy Unit with a pregnancy that is probably in the correct place but is too early for us to see.
- An early miscarriage has occurred. The pregnancy may have started but may have stopped growing (a miscarriage)
- The pregnancy is outside the uterus (womb) most commonly in the fallopian tube. This is called an 'ectopic' pregnancy. It is the least likely possibility but if ignored an ectopic pregnancy is potentially life threatening. Until we can see a pregnancy isnide the womb we cannot exclude an ectopic pregnancy
Ectopic pregnancy is one that is growing outside the uterus (womb). Often, an ectopic pregnancy grows in one of the Fallopian tubes. Around 1% of pregnancies are ectopic. An ectopic pregnancy is very serious and can be life threatening.
An ectopic pregnancy can happen to any woman. Some conditions make it more likely. These include:
- having had an ectopic pregnancy in the past
- diseases that affect the fallopian tubes
- having had abdominal surgery in the past
- a history of pelvic inflammatory disease (PID)
- an intrauterine device in place such as the copper "coil" or Mirena
- older age
What happens next?
Wait and rescan
If you have no worrying symptoms (pain and bleeding) and your period dates are compatible with a pregnancy that would be too early to see on the scan, then it is safe to wait and scan you again in a week's time (when we should hopefully see more clearly on the scan).
It is important that you are aware that we have not ruled out an ectopic pregnancy and if you have any pain, bleeding or feel unwell before you are due to come back to BPAS, you must seek medical attention straight away (either contact BPAS for another appointment, contact your GP or go to A&E).
Referral to Early Pregnancy Assessment Unit (EPAU)
If you have had pain or bleeding or your period dates are not compatible with seeing an empty uterus, the we may need to refer you for a more detailed assessment at an (EPAU). They can perform blood tests to look at the specific amount of pregnancy hormone in your blood, which together with a more detailed scan, gives more information to exclude or confirm an ectopic pregnancy. If an ectopic pregnancy is excluded you can return to BPAS to arrange treatment.
- In a normal pregnancy that is in the uterus (womb) we expect the pregnancy hormone level to double every 48 hours
- In an ectopic pregnancy the level will rise slightly or stay the same
- If a miscarriage has occurred the level should come down
We can refer you to an EPAU even if you are at low risk of ectopic pregnancy. Please tell the doctor or nurse if you want this option.
Signs or symptoms of ectopic pregnancy
If you choose to come back to BPAS in a week for another scan, you should know about worrying signs or symptoms to watch out for. These are:
- lower abdominal pain, especially if on one side and severe
- pain under the ribs or in the shoulders
- fainting or feeling light headed
- vaginal bleeding.
If you have any of these, seek medical advice immediately from:
- the nearest A&E department
- the Aftercare Line 0300 333 68 28 (or +44 1789 508 210)
- your GP
How can I get more information?
If you need any more information you should speak to a BPAS doctor or nurse, your GP or call the NHS non-emergency line by dialling 111.