Ectopic Pregnancy: Symptoms, hCG Levels, Ultrasound and Treatment

An ectopic pregnancy is a pregnancy that grows outside the uterus, almost always in a fallopian tube. It cannot continue to a birth, and as it grows it can make the tube burst and bleed inside the belly, which is a medical emergency. The most common ectopic pregnancy symptoms are a missed period with vaginal bleeding or spotting and pain low in the belly, often on one side.

The good news: when it is found early, an ectopic pregnancy is very treatable. Doctors diagnose it with a blood test for the pregnancy hormone hCG, repeated every 48 hours, and a transvaginal ultrasound. Treatment is a methotrexate injection, keyhole surgery or, in selected cases, close monitoring. Most people can have a successful pregnancy later.

Key takeaways

• Ectopic pregnancy affects an estimated 1% to 2% of pregnancies in the US, and more than 90% are in a fallopian tube.
• Sudden severe belly pain, shoulder-tip pain or fainting in early pregnancy can mean a rupture: call 999.
• No single hCG number diagnoses an ectopic pregnancy; what matters is how hCG changes over 48 hours together with the ultrasound.
• Methotrexate works best when hCG is low; after the shot, hCG is checked on days 4 and 7, then weekly until it is negative.
• Grief, anxiety and post-traumatic stress are common after an ectopic pregnancy, and asking for support is part of recovery.

What is an ectopic pregnancy?

Normally, a fertilised egg travels down a fallopian tube and implants in the lining of the uterus. In an ectopic pregnancy, it implants somewhere it cannot grow safely. According to the American College of Obstetricians and Gynecologists (ACOG), more than 90% of ectopic pregnancies are in a fallopian tube (a "tubal pregnancy"); rarely, they sit in the ovary, the cervix or the abdomen. A tube cannot stretch like the uterus, so it can rupture and bleed. An ectopic pregnancy cannot be moved into the uterus, so it always needs medical care.

How common is it, and is ectopic pregnancy dangerous?

A 2020 review in American Family Physician estimates that 1% to 2% of US pregnancies are ectopic. Deaths have fallen over the past decades, but it remains serious: in the CDC Pregnancy Mortality Surveillance System, ruptured ectopic pregnancy was the most frequent cause of pregnancy-related deaths from haemorrhage between 2012 and 2019, at 22.9% of them. Early diagnosis is what makes it safe.

Ectopic pregnancy causes and risk factors

Most ectopic pregnancies happen when something slows or blocks the egg's journey down the tube, often scar tissue. Infections such as chlamydia and gonorrhea, can cause pelvic inflammatory disease and damage the tube. ACOG and MedlinePlus list these risk factors:

• a previous ectopic pregnancy;
• surgery on the fallopian tubes, including having your tubes tied or untied;
• previous pelvic or abdominal surgery, including scarring after a ruptured appendix;
• pelvic inflammatory disease and some sexually transmitted infections;
• endometriosis;
• smoking, age over 35 and a history of infertility;
• assisted reproduction such as in vitro fertilization (IVF);
• getting pregnant with an intrauterine device (IUD or coil) in place.

Pregnancy with an IUD is rare (under 1%), but when it happens, up to 53% are ectopic, whether the IUD is copper or hormonal. After tubal sterilization, a positive test should be checked quickly; see our guide to symptoms after tubal ligation. One previous ectopic pregnancy brings a risk of about 10% in later pregnancies, and more than 25% after two or more.

Many people have no risk factor at all: about half, according to ACOG, and about a third, according to the National Institute for Health and Care Excellence (NICE).

Ectopic pregnancy symptoms

At first, an ectopic pregnancy can feel like any early pregnancy, and a home pregnancy test is positive. The signs of ectopic pregnancy that should prompt a call to your clinician are:

• vaginal bleeding or spotting, from light spotting to a flow like a period;
• pain in the lower belly or pelvis, often cramping on one side;
• low back pain;
• less often, digestive symptoms, urinary symptoms, pain when passing stool or a feeling of rectal pressure.

The pain often starts as one-sided cramps and may spread across the belly if the tube ruptures. NICE warns that atypical presentations are common and can look like a stomach bug or a urinary infection. Passing tissue (a decidual cast of the uterine lining) does not prove a miscarriage.

Signs of a ruptured ectopic pregnancy

• sudden, severe, sharp pain in the belly or pelvis;
• shoulder-tip pain;
• weakness, dizziness, fainting, a racing heart or low blood pressure;
• intense pressure in the rectum.

These are emergency signs: call 999 or go to the nearest A&E.

When do ectopic pregnancy symptoms start?

Symptoms usually appear in the first trimester. According to Cleveland Clinic, most people learn their pregnancy is ectopic around 8 weeks of pregnancy. Some notice spotting or one-sided cramps soon after a missed period; others have no symptoms until a scan. If your period is late and you have bleeding or pain with a positive test, it is worth being seen promptly rather than waiting for a routine first visit.

Conditions that can look similar

Doctors also consider an early miscarriage, ovarian torsion, pelvic infection, kidney stones and appendicitis; see our page on a burst appendix describes its warning signs.

How is an ectopic pregnancy diagnosed?

No single test settles it. Your care team combines your symptoms, a pelvic exam (which, according to American Family Physician, does not raise the risk of rupture), a transvaginal ultrasound and quantitative hCG blood tests.

The hCG blood test

Human chorionic gonadotropin (hCG) is made by the future placenta and can be detected in the blood as early as eight days after ovulation. A quantitative test reports the exact level in mIU/mL (the same number as IU/L). One value says little; our guide to hCG levels by week explains why. What helps is the trend between two tests 48 hours apart.

Transvaginal ultrasound

The scan looks for a pregnancy sac in the uterus and for a mass next to the ovary. A pregnancy seen in the uterus essentially rules out an ectopic pregnancy, except in the very rare heterotopic pregnancy. A yolk sac or embryo outside the uterus confirms the diagnosis, but most ectopic pregnancies never show this clearly, so repeat scans and blood tests are often needed.

The discriminatory zone, explained simply

The discriminatory level is the hCG value above which a pregnancy in the uterus should be visible on a transvaginal scan. It used to be 1,000 to 2,000 mIU/mL. Because some normal pregnancies show up a little later, American Family Physician recommends a level as high as 3,500 mIU/mL in a wanted pregnancy, while noting that most are seen by 1,500. An empty uterus above that level raises concern for an ectopic pregnancy or a pregnancy that is ending.

Pregnancy of unknown location

This means a positive test with no pregnancy seen on the scan. It is a temporary label, not a diagnosis: it turns out to be a very early pregnancy in the uterus, a pregnancy ending on its own, or an ectopic pregnancy. NICE advises treating it as a possible ectopic pregnancy until the location is known and taking two hCG measurements 48 hours apart. When a pregnancy is not wanted or cannot be viable, a uterine aspiration can find pregnancy tissue in the uterus and avoid unnecessary methotrexate.

Ectopic pregnancy hCG levels: thresholds at a glance

hCG in mIU/mL (the unit used in the US) equals hCG in IU/L (the unit used in UK laboratories). Hospitals may use slightly different cut-offs, always together with the scan and your symptoms.

The 48-hour figures come from American Family Physician. NICE uses simpler rules: a rise of more than 63% in 48 hours suggests a developing pregnancy in the uterus, a fall of more than 50% a pregnancy that will not continue, and anything in between calls for review within 24 hours.

How to read your hCG results

• A good rise with a pregnancy seen in the uterus is reassuring. An ectopic pregnancy is then very unlikely.
• A slow rise or a plateau does not confirm an ectopic pregnancy; it can also be a pregnancy in the uterus that is ending.
• A level above the discriminatory zone with an empty uterus is a reason for close review the same day or the next.
• A fall is often a miscarriage resolving, but follow-up continues until the test is negative.
• NICE recommends giving more weight to symptoms than to any number: new or worse pain needs a review, whatever the last result said.

Ectopic pregnancy treatment

The choice depends on whether you are stable, the hCG level, the scan, whether you can return for blood tests and your preferences. Signs of rupture mean urgent surgery.

Methotrexate: the shot and the follow-up

Methotrexate blocks dihydrofolate reductase, an enzyme fast-dividing cells need to use folate (ChEMBL CHEMBL34259). It stops the pregnancy cells from growing, and the body absorbs the tissue over 4 to 6 weeks, without removing the tube, according to ACOG. It is injected into a muscle, usually at 50 mg per square metre of body surface.

Before the shot, a complete blood count, liver function tests and a kidney test such as creatinine check that it is safe. It is not used with kidney or liver disease, moderate to severe anaemia, low blood cell counts, an active stomach ulcer or breastfeeding.

The follow-up is the key part:

1. Day 1: hCG test and injection.
2. Day 4: hCG test. A rise between days 1 and 4 is common and does not mean failure.
3. Day 7: hCG test. It should fall by more than 15% between day 4 and day 7. If it does not, a second dose or surgery is discussed.
4. Then weekly hCG tests until the result is negative, which can take up to eight weeks.

The two-dose protocol adds an injection on day 4 and works better when hCG is higher; American Family Physician suggests a single dose below about 3,600 mIU/mL. Success falls as the starting hCG rises: single-dose methotrexate worked in 98% of cases under 1,000 mIU/mL, 94% at 1,000 to 1,999, 96% at 2,000 to 4,999, 85% at 5,000 to 9,999 and 81% at 10,000 or more.

Belly pain for two to three days after the injection is common, as are nausea and spotting. During treatment, ACOG advises avoiding alcohol, folic acid and folate-rich foods, NSAIDs such as ibuprofen, sex, heavy exercise, long sun exposure and gassy foods that can mask pain. The risk of rupture lasts until hCG is negative.

Ectopic pregnancy surgery

Surgery is usually done by laparoscopy, through small cuts, under general anaesthesia. A salpingectomy removes the affected tube; a salpingotomy (or salpingostomy) removes the pregnancy and keeps the tube. NICE recommends a salpingectomy unless you have other risk factors for infertility, such as damage to the other tube. After a salpingotomy, up to 1 in 5 people need further treatment and weekly hCG tests follow; after a salpingectomy, a urine pregnancy test at 3 weeks is enough.

Expectant management

For small, stable ectopic pregnancies with low hCG, close watching is an option (see the table), with blood tests on days 2, 4 and 7, then weekly. When the starting hCG is 200 mIU/mL or less, about 88% resolve on their own.

Rh factor, blood loss and other checks

After heavy bleeding, your haemoglobin is checked; see our guide to anaemia symptoms and tests. Your blood group is checked too. If you are Rh negative, ask whether you need anti-D (Rh immune globulin); our page on the Rh system in pregnancy explains why. Advice changed recently (see below), and practice may differ between countries.

Recovery, emotions and future fertility

Many people feel tired for several weeks, and periods may take a few cycles to settle. An ectopic pregnancy is a pregnancy loss, often combined with fear. A London study of 737 women after early pregnancy loss found that 9 months after an ectopic pregnancy, 21% still met criteria for post-traumatic stress, 23% for moderate to severe anxiety and 11% for depression. These feelings are common and treatable. ACOG suggests counselling and online or peer support from others who have been through it.

Most people can still get pregnant, and there is no evidence that methotrexate harms fertility. Ask for an early check of the location in your next pregnancy, as the risk of another ectopic pregnancy is higher. After methotrexate, wait at least one ovulatory cycle once hCG is negative; some experts advise three months.

Can you prevent an ectopic pregnancy?

Not always. You can lower some risks: practice safer sex, get tested and treated early for sexually transmitted infections, and stop smoking. If you are at higher risk, contact your clinician as soon as a pregnancy test is positive.

When to see a doctor

Contact your clinician or an early pregnancy service the same day if:

• you have a positive pregnancy test with vaginal bleeding or pain in your lower belly or pelvis;
• you have had a previous ectopic pregnancy, tubal surgery or IVF, or you became pregnant with an IUD or after tubal ligation;
• you have pain after methotrexate or surgery that does not improve with over-the-counter pain relief.

Call 999 or go to A&E right away for sudden or severe belly pain, shoulder-tip pain, fainting, dizziness, a racing heart or heavy bleeding.

Latest scientific advances in ectopic pregnancy

Gefitinib plus methotrexate: a clear "no" from the GEM3 trial (2023)

Gefitinib, a pill that blocks the epidermal growth factor receptor (ChEMBL CHEMBL939), was tested with methotrexate in the GEM3 trial (The Lancet, 2023): 328 people in 50 UK hospitals. Surgery was still needed in 30% with gefitinib and 29% with placebo, and gefitinib added diarrhoea and rash. Methotrexate alone remains the standard.

An earlier sign that methotrexate is working (2023)

In 322 GEM3 participants with hCG between 1,000 and 5,000 IU/L, any fall in hCG between day 1 and day 4 meant an 85% chance that a single dose would succeed. The authors suggest reassuring people whose hCG falls, or rises by less than 18%, by day 4. Overall, a single dose worked in 59% of this group, so follow-up still matters.

Letrozole: a promising pill, not yet a standard (2024-2026)

Letrozole blocks aromatase (CYP19A1), the enzyme that makes oestrogen (ChEMBL CHEMBL1444). In a 2024 randomised trial (NCT05918718) of 88 women with hCG under 3,000 mIU/mL, treatment worked in 76.7% with methotrexate, 75.0% with 5 days of letrozole and 90.5% with 10 days, without a significant difference. A 2025 meta-analysis of 260 patients found similar success, but rated the evidence as very low certainty. A trial is recruiting in Brazil (NCT06354439); for now, letrozole stays in research.

Smarter follow-up for a pregnancy of unknown location (2024-2026)

The M6 model uses two hCG results 48 hours apart to sort a pregnancy of unknown location into low or high risk. In a 2024 French study of 341 women, it caught 90.6% of ectopic pregnancies, a low-risk result was right 98.4% of the time, and it could have spared about 4.5 visits per patient. In a US multicentre trial analysis, two-dose methotrexate for a persisting pregnancy of unknown location cost the least and led to fewer tube removals than watchful waiting (1.2% versus 9.4%). A University of Pennsylvania trial started in 2026 is testing hysteroscopy for these pregnancies (NCT07469605).

New UK guidance on anti-D after early pregnancy loss (June 2026)

In June 2026, NICE updated guideline NG126: anti-D immunoglobulin is no longer offered for an ectopic pregnancy or miscarriage up to 11 weeks and 6 days, for lack of evidence of benefit. At 12 weeks, at least 250 IU is still offered to RhD-negative people having medical or surgical treatment. Practice varies by country.

Which tests can help?

If you are pregnant with pain or bleeding, the key tests are a quantitative hCG repeated after 48 hours and a transvaginal ultrasound. Around them, a typical work-up adds:

• a blood count to look for anaemia from blood loss and to check platelets before methotrexate;
• liver enzymes and kidney function before methotrexate, and sometimes again during treatment;
• tests for chlamydia and gonorrhea when an infection may have damaged the tubes;

Glossary

• Ectopic pregnancy: a pregnancy that implants outside the uterus, usually in a fallopian tube.
• hCG (human chorionic gonadotropin): the pregnancy hormone measured in urine and blood tests.
• Discriminatory zone: the hCG level above which a pregnancy in the uterus should be seen on a transvaginal scan.
• Pregnancy of unknown location: a positive pregnancy test with no pregnancy seen on ultrasound yet.
• Transvaginal ultrasound: a scan done with a slim probe placed in the vagina, which gives a close view of the uterus and tubes.
• Methotrexate: a drug that stops fast-growing pregnancy cells, given as an injection.
• Salpingectomy: surgery that removes a fallopian tube.
• Salpingotomy: surgery that removes the pregnancy and keeps the tube.
• Anti-D immunoglobulin: an injection that prevents an Rh-negative person from making antibodies against Rh-positive blood.

Frequently asked questions

What are the symptoms of an ectopic pregnancy?

A missed period, vaginal bleeding or spotting and pain in the lower belly or pelvis, often on one side, sometimes low back pain. Sudden severe pain, shoulder-tip pain or fainting can mean a rupture: call 999.

Can an ectopic pregnancy survive or be carried to term?

No. A pregnancy outside the uterus cannot develop into a baby and cannot be moved into the uterus. Treatment protects your health and your fertility.

Is an ectopic pregnancy a miscarriage?

Not exactly. A miscarriage is the loss of a pregnancy growing in the uterus, while an ectopic pregnancy grows outside it and needs specific monitoring or treatment. Both are early pregnancy losses, and the grief can be just as real.

What happens when you're having an ectopic pregnancy?

The pregnancy grows in the tube and hCG often rises more slowly than expected. Found before a rupture, it is treated with methotrexate, surgery or close monitoring. If the tube ruptures, internal bleeding causes severe pain and dizziness, and emergency surgery is needed.

When does ectopic pregnancy pain start?

Usually in the first trimester, and most ectopic pregnancies are found around 8 weeks of pregnancy. Mild one-sided cramping can come first, while sudden severe pain suggests a rupture.

Can I get pregnant after an ectopic pregnancy?

Yes, most people can. In the ESEP trial of 446 women with a healthy other tube, 60.7% had a natural ongoing pregnancy within three years after salpingotomy and 56.2% after salpingectomy.

Sources

• American College of Obstetricians and Gynecologists — Ectopic Pregnancy (FAQ) — ACOG — acog.org
• MedlinePlus — Ectopic pregnancy — National Library of Medicine, reviewed 2026 — medlineplus.gov
• National Institute for Health and Care Excellence — Ectopic pregnancy and miscarriage: diagnosis and initial management (NG126) — NICE, 2019, updated June 2026 — nice.org.uk
• Cleveland Clinic — Ectopic Pregnancy — Cleveland Clinic — clevelandclinic.org
• Hendriks E, Rosenberg R, Prine L — Ectopic Pregnancy: Diagnosis and Management — Am Fam Physician, 2020 — pubmed.ncbi.nlm.nih.gov
• Hollier LM et al. — Pregnancy-Related Deaths Due to Hemorrhage: Pregnancy Mortality Surveillance System, 2012-2019 — Obstet Gynecol, 2024 — doi.org
• Horne AW et al. — Combination of gefitinib and methotrexate to treat tubal ectopic pregnancy (GEM3) — Lancet, 2023 — doi.org
• Mackenzie SC et al. — Early (Days 1-4) post-treatment serum hCG level changes predict single-dose methotrexate treatment success in tubal ectopic pregnancy — Hum Reprod, 2023 — doi.org
• Tarafdari A et al. — Comparing the effectiveness of letrozole versus methotrexate for treatment of ectopic pregnancy: a randomized controlled trial — Eur J Obstet Gynecol Reprod Biol, 2024 — doi.org
• Abu-Zaid A et al. — Efficacy of Monotherapy Letrozole Versus Methotrexate for the Management of Ectopic Pregnancy: A Systematic Review and Meta-Analysis — J Clin Med, 2025 — doi.org
• Mol F et al. — Salpingotomy versus salpingectomy in women with tubal pregnancy (ESEP study) — Lancet, 2014 — doi.org
• Farren J et al. — Posttraumatic stress, anxiety and depression following miscarriage and ectopic pregnancy: a multicenter, prospective, cohort study — Am J Obstet Gynecol, 2020 — doi.org
• Maheut C, Panjo H, Capmas P — Diagnostic accuracy validation study of the M6 model without initial serum progesterone in triage of pregnancy of unknown location — Eur J Obstet Gynecol Reprod Biol, 2024 — doi.org
• Walter JR et al. — Cost-effectiveness analysis of expectant vs active management for treatment of persistent pregnancies of unknown location — Am J Obstet Gynecol, 2024 — doi.org
• ClinicalTrials.gov — Use of Letrozole in the Treatment of Early Ectopic Pregnancy (NCT06354439) — clinicaltrials.gov
• ClinicalTrials.gov — Hysteroscopy for the Diagnosis and Treatment of Pregnancy of Unknown Location (NCT07469605) — clinicaltrials.gov
• ChEMBL — Methotrexate (CHEMBL34259): dihydrofolate reductase inhibitor — EMBL-EBI — ebi.ac.uk
• ChEMBL — Letrozole (CHEMBL1444) and gefitinib (CHEMBL939): mechanisms of action — EMBL-EBI — ebi.ac.uk
• NHS — Ectopic pregnancy — National Health Service — nhs.uk

Further reading

• Blood tests during pregnancy: what is checked
• Fertility blood test: which hormones to check
• Ovulation spotting: timing, causes and red flags
• Ovary pain after sex: causes, tests and relief
• Haemoglobin levels: what your blood test means
• O negative blood type: donation, pregnancy and risks

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