Ectopic Pregnancy Diagnosis

Urinary pregnancy tests

The first, useful basic test is a urinary pregnancy test. These tests check for human Chorionic Gonadotropin (hCG), a pregnancy hormone produced by a fertilised egg after conception. Urinary pregnancy tests can sometimes produce a negative result in pregnancy because the human Chorionic Gonadotropin hormone level is not yet high enough. A positive pregnancy test would usually show if human Chorionic Gonadotropin levels are elevated.

Ultrasound scanning

Whether you have a positive pregnancy test or not, if you have ectopic pregnancy symptoms, it is recommended to speak to your local doctor (GP) or early pregnancy assessment unit (EPAU). If they decide an ultrasound scan (ultrasonography) is appropriate, this will be arranged within 24 hours. It is likely that a transvaginal (internal) ultrasound scan will be required, where a specialised probe is placed into the vagina to get a more detailed look at the reproductive organs. A transvaginal ultrasound scan is safe in pregnancy.

If during the scan a pregnancy – that is a gestation (pregnancy) sac, a foetal pole and a beating heart – can be seen in the uterus (womb), the chance of a coexisting ectopic pregnancy, whilst possible is rare (heterotopic pregnancy). Nonetheless, a complete check will be performed with every ultrasound scan.

If pregnancy is seen in the uterus, vaginal bleeding may be due to implantation and development of the fertilised egg during a healthy pregnancy, or a sign of an impending miscarriage. Pelvic pain may be caused by a normal, healthy corpus luteum cyst, which forms on the ovary after every ovulation, swelling to cause pain. Changes to the bowel and bladder may be attributed to changes in hormones, causing you to pass urine (wee) more often and possibly even be a little constipated (hard to open the bowels to have a poo).

If a pregnancy cannot be seen in the uterus, but there is evidence of internal bleeding and/or swelling in the approximate location of the Fallopian tubes (tubal pregnancy), your doctor will likely suspect a risk of ectopic pregnancy. An initial transvaginal scan will detect over 70% of ectopic pregnancies, and most ectopic pregnancies will be seen as an area of pregnancy tissue, with or without a gestational sac, a fetal pole or a beating heart that is not correctly placed in the uterus.

Pregnancy of Unknown Location (PUL)

If pregnancy cannot be seen inside or outside the uterine cavity (womb), or if the sonographer is not certain, you may hear this situation being classified as a Pregnancy of Unknown Location, or PUL. It is important to understand that PUL is not a diagnosis; it is a label given until the final location of the pregnancy can be identified with certainty. It is also important to note that this classification does not necessarily mean there is an ectopic pregnancy, as PUL also include healthy intrauterine pregnancies that are initially too small to see on ultrasound scans as well as failing pregnancies that are too small to visualise.

In the event of a PUL, blood tests will be taken to measure hCG (the same hormone measured in urinary pregnancy tests) and another pregnancy hormone called progesterone. The hCG test may be repeated 48 hours later depending on the first results, and this will help the doctors plan if a follow-up ultrasound scan is needed in order to identify the location of the pregnancy.

The reason for this is that until the location of the pregnancy is known with certainty, or the hormone levels have decreased to below pregnancy levels, there is a risk of complications associated with an ectopic pregnancy which has not yet been identified. For every 100 pregnancies initially classified as a PUL, approximately 12 will subsequently receive an ectopic pregnancy diagnosis. Importantly, of these 12, some will not need any treatment. Your doctors will discuss the possible treatment options with you.

All PUL will be followed up until a final early pregnancy location is confirmed as ectopic, or within the uterine cavity. Sometimes a location cannot be confirmed, which is why the hormone level tests may continue for a little longer.

In certain circumstances, a diagnostic laparoscopy or laparotomy may be necessary especially if there is suspicion of ruptured ectopic pregnancy.

Human Chorionic Gonadotropin (hCG) and progesterone blood tests

The hormone hCG is produced during early pregnancy as soon as the body detects that a fertilised egg is present in the body, It is produced by the developing placenta regardless of where the pregnancy is. hCG levels can first be detected by a blood test approximately 11 days after conception and, in a healthy pregnancy, will typically increase during the first 8 to 11 weeks of pregnancy (first trimester), then fall or level off for the remainder of the pregnancy. It is hCG that leads to the ‘morning sickness’ some experience in early pregnancy.

Progesterone is the hormone made by the corpus luteum cyst, which forms on the ovary after every ovulation. If not pregnant, progesterone is only made for two weeks, after which the corpus luteum disappears, a period starts, and a new cycle begins. In pregnancy, this cyst is encouraged to remain and continue releasing progesterone for the first 13 weeks of early pregnancy (first trimester).

HCG and progesterone are used to guide the management of a PUL. The progesterone is measured at the time of the first visit by some doctors, whilst the hCG level is measured at the first visit and then in most cases 48 hours later. Low progesterone and falling hCG levels may indicate the pregnancy is no longer growing, or that the pregnancy has unfortunately already passed as a miscarriage.

High progesterone and normally rising hCG results are associated with a pregnancy that is still present, even if it is not visible on a scan. In this situation, the pregnancy is most likely to be in the correct place in the uterus. Occasionally, however, the hCG levels rise suboptimally, and this can indicate the development of an ectopic pregnancy. The doctor caring for you will interpret these results in order to plan the treatment options and next steps of your care safely.

HCG is also used to help decide the best treatment for ectopic pregnancy. These laboratory findings will be assessed by your doctor alongside your symptoms and your ultrasound scan findings. Ectopic pregnancy might be treated with methotrexate if hCG levels are not more than 5000 IU/l and depending on the clinical situation. When hCG levels are very low and decreasing and if the clinical situation is stable, expectant management may be available. If there is internal bleeding as a result of ruptured ectopic pregnancy, emergency surgery is essential for this life-threatening condition.

Your feelings when diagnosed with an ectopic pregnancy

Going through any diagnostic procedure can be very stressful and worrying, particularly when the potential outcome or final outcome is pregnancy loss. It is important to try to ensure you seek the emotional and physical support you need during both the diagnosis and then both during and after treatment.

Please read more about your emotional journey and others who have shared their experience by reading our emotions page or reading through our personal stories collection.

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