Ectopic Pregnancy — Causes, Beta-hCG Testing, Salpingectomy & Methotrexate Guide — Symptoms, Causes & Treatment | MyMedicPlus

An ectopic pregnancy is one that implants outside the uterine cavity — most commonly (95%) in the fallopian tube (tubal ectopic), and rarely in the ovary, cervix, interstitium of the uterine cornua, abdominal cavity, or caesarean scar. The fertilised egg cannot develop normally outside the uterus — ectopic pregnancies are not viable. Ectopic pregnancy affects approximately 1–2% of all pregnancies and is the leading cause of maternal mortality in the first trimester of pregnancy, accounting for approximately 9% of pregnancy-related deaths. Rupture of a tubal ectopic pregnancy causes intraperitoneal haemorrhage and can be rapidly fatal. Early diagnosis using serum beta-hCG measurement and transvaginal ultrasound (TVUS) enables management before rupture in most cases. Three management options exist: expectant (watchful waiting), medical (methotrexate), and surgical (laparoscopic salpingectomy or salpingotomy).

An ectopic pregnancy results when the fertilised egg cannot travel normally through the fallopian tube to reach the uterine cavity — most often due to damage or dysfunction of tubal cilia or muscle. Principal risk factors: Previous ectopic pregnancy — the most important risk factor (risk of recurrence approximately 10–15% after one ectopic, 25–30% after two). Previous tubo-peritoneal surgery (tubal surgery — tubal ligation, reversal, salpingostomy — adhesiolysis). Pelvic inflammatory disease (PID): Chlamydia trachomatis and Neisseria gonorrhoeae infections cause peritubal scarring and tubal damage — PID is responsible for 50% of ectopic pregnancies. Endometriosis: peritubal adhesions impair ovum transport. In vitro fertilisation (IVF) and assisted reproductive technology: ectopic rates are higher (2–5% versus 1–2% spontaneous conception) — possibly due to embryo migration or underlying tubal pathology. Intrauterine device (IUD): not a cause of ectopic pregnancy, but if pregnancy occurs despite an IUD, there is a higher relative probability it is ectopic (IUD prevents intrauterine implantation more effectively than extrauterine). Smoking (dose-dependent tubal cilia dysfunction). Older age (over 35). Progestogen-only pill (low-dose POP) was historically associated but modern POPs do not significantly increase risk.

Classic triad (present in only 45% of cases): amenorrhoea (missed period), irregular vaginal bleeding (often brown, scanty, or 'spotting'), and unilateral lower abdominal/pelvic pain. Importantly, many ectopic pregnancies present atypically — some women do not know they are pregnant; bleeding may be mistaken for an unusual period; pain may be mild or absent. Before rupture: unilateral (typically one-sided) lower abdominal pain; shoulder-tip pain (referred pain from diaphragmatic irritation by blood — suggests haemoperitoneum even before rupture); nausea, vomiting; vaginal bleeding. On examination: unilateral adnexal tenderness; cervical excitation (extreme tenderness on moving the cervix — 'cervical os tenderness') — a classic sign of ectopic; uterus smaller than expected for gestational age; adnexal mass may be palpable. Rupture (emergency): sudden-onset severe lower abdominal pain; rapid progression to haemodynamic instability (tachycardia, hypotension, pallor, collapse); peritonism (rigid abdomen, rebound tenderness); shock — can be rapidly fatal.

Urinary pregnancy test (urine hCG): confirms pregnancy in any woman of reproductive age with abdominal pain and/or vaginal bleeding — all such women should have a pregnancy test before assuming a gynaecological or gastrointestinal cause. Serum beta-hCG (quantitative): the cornerstone of ectopic pregnancy monitoring. In a normal intrauterine pregnancy, beta-hCG doubles approximately every 48 hours; in ectopic or failing pregnancy, the rise is slower (below 50% increase over 48 hours). Serial serum beta-hCG levels at 48-hour intervals guide management. The 'discriminatory zone' (beta-hCG level above which an intrauterine pregnancy should be visible on TVUS): approximately 1000–1500 IU/L for TVUS — if beta-hCG above this level and no intrauterine pregnancy seen, ectopic or pregnancy of unknown location is diagnosed. Transvaginal ultrasound (TVUS): the primary imaging modality — performed in an Early Pregnancy Assessment Unit (EPAU); identifies intrauterine pregnancy (effectively excludes tubal ectopic in most cases); may directly visualise a tubal ring (ectopic gestational sac — a 'bagel sign') with or without fetal cardiac activity; identifies free fluid in the pelvis or pouch of Douglas (haemoperitoneum). Pregnancy of unknown location (PUL): no intrauterine pregnancy and no clear ectopic on TVUS — requires serial beta-hCG and repeat TVUS. Diagnostic laparoscopy: definitive if imaging inconclusive and clinical suspicion high.

Emergency (rupture or haemodynamic instability): immediate resuscitation (IV access x2, IV fluids, crossmatch and blood transfusion, oxygen); emergency laparotomy or laparoscopy — salpingectomy (removal of the affected fallopian tube). Expectant management: appropriate for clinically stable patients with a small, asymptomatic ectopic, declining serial beta-hCG (below 1000 IU/L and falling) — spontaneous resolution occurs in 57–70% of PUL and carefully selected tubal ectopics; requires close monitoring with serial beta-hCG every 2–7 days until undetectable. Medical management (methotrexate): folate antagonist — inhibits trophoblast cell proliferation; given as single intramuscular dose 50 mg/m2 body surface area; second dose on day 7 if beta-hCG has not fallen more than 15% from days 4 to 7; suitable patients: haemodynamically stable, beta-hCG below 3000 IU/L (some guidelines allow up to 5000 IU/L), ectopic smaller than 3.5 cm on TVUS, no fetal cardiac activity, willing and able to attend follow-up. Success rate: 70–80% single dose; 90% with second dose. Contraindications: breastfeeding, renal or hepatic impairment, immunodeficiency, peptic ulcer disease, pulmonary disease. Post-methotrexate care: avoid folate supplements, NSAIDs, alcohol, and sun exposure for at least 2 weeks; avoid conception for 3 months; serial beta-hCG until undetectable (typically 3–4 weeks). Surgical management: laparoscopic salpingectomy (removal of the affected tube — preferred over salpingotomy except when the contralateral tube is damaged or absent; reduces recurrent ectopic risk); laparoscopic salpingotomy (incision and removal of the ectopic while preserving the tube — 20% require follow-up methotrexate for persistent trophoblast; may be preferred if only one tube). Anti-D immunoglobulin: 250–500 IU IM must be given to all Rh-negative women undergoing surgical or medical treatment for ectopic pregnancy to prevent Rhesus isoimmunisation.

Ectopic pregnancy causes life-threatening and long-term reproductive complications. Rupture with haemoperitoneum: the most immediately dangerous complication — a ruptured ectopic pregnancy causes massive intraperitoneal haemorrhage, haemodynamic shock, and can be fatal within minutes to hours without emergency surgery; rupture occurs in approximately 15–20% of ectopic pregnancies and is the leading cause of maternal death in the first trimester in high-income countries. Fallopian tube damage: salpingectomy (removal of the affected tube) reduces tubal function; approximately 10–15% of women have a recurrent ectopic pregnancy in subsequent pregnancies after one ectopic. When both tubes are damaged or absent after bilateral salpingectomy, natural conception becomes impossible and IVF is required. Psychological impact: ectopic pregnancy constitutes pregnancy loss and causes grief, anxiety, depression, and PTSD symptoms in a significant proportion of women — psychological support should be routinely offered. Methotrexate side effects: nausea, mucositis, and transient elevated liver enzymes; persistence of trophoblastic tissue (persistent ectopic) occurs in approximately 10–20% after salpingotomy, requiring additional medical or surgical treatment. Rh sensitisation: if anti-D immunoglobulin is not given to Rh-negative women, future pregnancies may be complicated by haemolytic disease of the newborn. Anaemia and need for blood transfusion complicates cases of significant haemoperitoneum, and surgical complications (bowel injury, port site hernia, anaesthetic risks) accompany emergency laparoscopy.

Prevention of risk factors: treat pelvic inflammatory disease promptly and completely (test for Chlamydia and gonorrhoea — with contact tracing); annual Chlamydia screening for sexually active women under 25; consistent condom use reduces STI transmission and PID risk; smoking cessation (dose-dependent tubal dysfunction). After an ectopic pregnancy: future fertility depends on the condition of the remaining tube, the woman's age, and the management approach. Overall, 60–65% of women achieve a subsequent intrauterine pregnancy after one ectopic (higher if managed medically or with salpingotomy, preserving the tube — though salpingotomy does not significantly improve fertility versus salpingectomy in most trials). Recurrence risk is approximately 10–15% after one ectopic pregnancy — women should be advised to seek early assessment in subsequent pregnancies (TVUS and beta-hCG at 6–7 weeks) and report any early pregnancy symptoms promptly. IVF may be offered after tubal ectopic, especially if the remaining tube is damaged.

Ectopic pregnancy is a medical emergency — early recognition is life-saving. Any sexually active woman of reproductive age should take a pregnancy test if she experiences: lower abdominal or pelvic pain (especially one-sided); unusual or unexpectedly light vaginal bleeding; a missed or late period. If the test is positive AND you have pelvic pain or bleeding, attend an Emergency Department or Early Pregnancy Assessment Unit (EPAU) immediately — do NOT wait for a routine GP appointment. Call emergency services (999/112/911) immediately for: sudden severe lower abdominal pain; pain radiating to the shoulder tip; dizziness, fainting, rapid heartbeat, or collapse — these may indicate rupture with internal bleeding, which is life-threatening within minutes to hours. After treatment for an ectopic, always attend all follow-up appointments, and inform your doctor of any new pain or symptoms.