Obstetrics and Gynecology & Family Medicine & Emergency Medicine
Ectopic pregnancy
Ectopic pregnancy (EG), or ectopic pregnancy (EP), is defined by the implantation and development of the blastocyst outside the endometrial cavity. In 95 % of cases, implantation occurs in the Fallopian tube - most often in the ampullary portion. Less frequent locations include the uterine horn, cervix, ovary, peritoneal surface and, in the case of Caesarean section scars, the isthmic myometrium. Ectopic pregnancy accounts for 1 to 2 % of all pregnancies, and is the leading cause of maternal mortality in the first trimester of pregnancy in high-income countries, due to the risk of tubal rupture leading to massive intra-abdominal hemorrhage and hypovolemic shock. In Quebec, the incidence is around 12 cases per 1,000 pregnancies. Diagnosis is based on the clinical triad of pelvic pain, metrorrhagia and amenorrhea, combined with serial beta-hCG measurement and transvaginal ultrasound. Depending on the hemodynamic status, location and characteristics of the ectopic pregnancy, management may be medical (methotrexate), surgical (salpingostomy or salpingectomy) or conservative (expectant monitoring in EGs with spontaneous resolution). Future fertility depends on the speed of diagnosis and choice of treatment.
Pathophysiology, risk factors, and locations
- Mechanisms of ectopic implantation and pathophysiology: normal migration of the fertilized ovum: after fertilization in the ampullary portion of the tube → the zygote is transported to the uterine cavity in 3-5 days by ciliary motility + tubal peristaltic contractions → implantation in the endometrium around D6-J7; mechanisms leading to ectopic implantation : impaired tubal motility (main cause): sequelae of infections (Chlamydia trachomatis salpingitis ++ + Neisseria gonorrhoeae) → fibrosis + peritubal adhesions + partial destruction of cilia → slowing or blocking of tubal transit → implantation in the tube + anatomical tubal obstruction: previous tubal surgery (sterilization + salpingostomy) + pelvic adhesions (endometriosis + peritonitis) + congenital tubal malformations + altered endometrial receptivity: DES (diethylstilbestrol - in utero exposure) → tubal + uterine anomalies + smoking: reduces tubal ciliary motility + increases ectopic receptivity + pregnancy under IUD (intrauterine device): the IUD protects against intrauterine pregnancy but not against ectopic pregnancy → if pregnancy occurs under IUD → risk of GE × 6-10 + IVF (in vitro fertilization): embryo transfer → tubal reflux possible → GE in 2-3 % of IVF cycles - higher if pathological tubes (hydrosalpinx); natural course of untreated tubal pregnancy: trophoblast growth → erosion of tubal mucosa and muscularis → intratubal bleeding → hematosalpinx → tubal rupture (peak between 6 and 10 SA) → intra-abdominal hemorrhage → hemoperitoneum → hypovolemic shock → life-saving surgical emergency → untreated mortality: >10 % per rupture; particularity of rare localizations: horn or interstitial pregnancy (2-4 % of GE): uterotubal angle → difficult diagnosis + late rupture (10-14 SA) + greater haemorrhage (better vascularized myometrium) → higher mortality than tubal GE + Caesarean Scar Pregnancy (CSP): increasing incidence with rising caesarean section rates → risk of placenta accreta + percreta → specific treatment (methotrexate + embolization + conservative surgery) + heterotopic pregnancy (simultaneous GE + intrauterine pregnancy): rare spontaneously (1/30,000) but more frequent after IVF (1/100-1/3,000) → diagnostic pitfall → intrauterine pregnancy may mask GE
- Risk factors — identification in clinical practice: major risk factors (relative risk >4): history of ectopic pregnancy (risk of recurrence : 10-15 % after a 1st GE + 25-30 % after two GEs) + history of tubal surgery (tubal sterilization + salpingostomy) + ongoing tubal sterilization (sterilization failure → if pregnancy → 50 % of GE) + history of salpingitis or documented STI (Chlamydia ++ - 30 % of GE have a history of STI) + pregnancy on IUD in place + IVF or other medically assisted reproduction techniques (MAP) + in utero exposure to DES (cohorts of women born before 1971) ; moderate risk factors (relative risk 2-4) : smoking (dose-dependent) + multiple sexual partners (increased risk of STIs) + history of pelvic or abdominal surgery (complicated appendicitis + ovarian surgery + myomectomy) + endometriosis + infertility + age ≥35 years (reduced ciliary motility); low risk factors (relative risk 1-2): vaginal douches (vaginal dysbiosis → ascending STIs) + pregnancy after tubal ligation under exogenous estrogens (contraceptives); absence of risk factors: 30-50 % of patients with GE have no identifiable risk factors → GE should be evoked in any woman of childbearing age presenting with pelvic pain + metrorrhagia whatever the context
- Clinical presentation and deceptive forms: classic clinical triad: pelvic pain (unilateral - side of implantation - may radiate to the shoulder - Laffont's sign - if hemoperitoneum irritating the diaphragm) + metrorrhagia (scanty brown or blackish bleeding - «strong coffee») + amenorrhea (4-8 week delay in menses - may be unrecognized if irregular cycles) - complete triad: 45-50 % only → isolated pain or isolated metrorrhagia: frequent → always measure beta-hCG in a woman of childbearing age presenting either of these symptoms; clinical forms according to evolution: unruptured GE (stable patient - the majority of cases diagnosed early): moderate pain + light metrorrhagia + pelvic examination: adnexal tenderness + possible adnexal mass + uterus of normal size (or slightly increased by the hormonal effects of pregnancy) → diagnosis by beta-hCG + transvaginal ultrasound + ruptured GE (surgical emergency): sudden intense abdominal pain («stabbing») ± syncope + signs of hypovolemic shock (tachycardia + hypotension + pallor + mottling + polypnoea) + diffuse abdominal defence + Douglas sign (exquisite pain on palpation of the cul-de-sac of Douglas on vaginal touch) + blood count: acute anemia + reactive leukocytosis → immediate emergency surgery; misleading forms: EW during tubal abortion: intratubal hemorrhage gradually resolved + beta-hCG already falling → may simulate early miscarriage → serial beta-hCG essential + EW of cornual or interstitial location: may be asymptomatic for longer + late rupture (10-14 SA) + catastrophic rupture picture → high vigilance
Diagnosis, medical and surgical treatment
| Clinical situation | Diagnosis | Treatment and follow-up |
|---|---|---|
| Diagnostic assessment of GE Serial beta-hCG — TV ultrasound — discriminatory zone |
Diagnosis of ectopic pregnancy relies on the combination of serial quantitative beta-hCG and transvaginal ultrasound - neither test is sufficient on its own in uncertain cases; quantitative beta-hCG (human chorionic gonadotropin - beta fraction): measured on venous serum - diagnostic threshold value: any result >0 IU/L confirms a progressive or recent pregnancy → absolute value alone is insufficient to locate the pregnancy → beta-hCG kinetics are decisive: normal progressive intrauterine pregnancy: doubling of beta-hCG every 48h to ~10,000-20,000 IU/L → elevation discriminating zone + absence of intrauterine gestational sac → GE very likely (except complete miscarriage or multiple pregnancy); transvaginal ultrasound (TVS): reference examination - to be performed systematically in any pregnancy with suspicious symptoms → signs to look for : intrauterine gestational sac (IUS) with yolk bladder ± embryo → probable intrauterine pregnancy → but heterotopic pregnancy possible if IVF + extra-ovarian adnexal mass (most specific sign of tubal GE - «blob sign» or tubal ring - sensitivity 87-99 % + specificity 94-99 %) + fluid in the cul-de-sac de Douglas (hemoperitoneum → if abundant → probable rupture) + absence of IUS + adnexal mass → very probable GE (PPV 95 %) + absence of IUS + no mass + low beta-hCG (< discriminating zone) → pregnancy of unknown location (GLI - Pregnancy of Unknown Location - PUL) → serial monitoring ; Douglas puncture (culdocentesis): non-coagulating blood in the cul-de-sac of Douglas → hemoperitoneum → ruptured GE → historical examination - replaced by ultrasound in most centers → still used if ultrasound not available urgently | Decision algorithm based on beta-hCG and ultrasound: beta-hCG + ETV → intrauterine sac with embryo or yolk bladder → intrauterine pregnancy → usual obstetrical follow-up (exclude GH if IVF) + high beta-hCG + typical adnexal mass on ETV → confirmed GE → treatment according to eligibility criteria + betahCG low plateauing or falling + non-contributory ETV → spontaneous abortion in progress or GE resolving → serial monitoring (beta-hCG at D0 + D4 + D7) → if progressive fall → spontaneous resolution + if plateau or rise → active GE → treatment ; other complementary tests : CBC + blood group + rhesus + RAI (anti-D immunization if Rh negative → anti-D immunoglobulins indicated if surgery or heavy bleeding) + PT + APTT + fibrinogen (if surgery or hemorrhagic shock) + creatinine + liver workup (premethotrexate) + CBC + reticulocytes (pre-operative anemia) + culdocentesis or color Doppler ETV if doubt → vascularization of adnexal mass → highly vascularized trophoblast (ring of fire on Doppler) → strong argument for GE ; pregnancy of unknown location (PUL): definition: beta-hCG positive + ETV with no identifiable intrauterine sac or ectopic mass → 3 possible evolutions: spontaneous miscarriage (50-70 %) + GE (7-20 %) + early intrauterine pregnancy still not visible (15-20 %) → monitoring: beta-hCG at D0 + D2 + D4 + D7 → if ratio D0/J2 1.66 → probable evolutive GI → if in between → possible GE → control ETV at 48-72h |
| Medical treatment — methotrexate Eligibility Criteria — Single Dose Protocol — Beta-hCG Follow-up |
Methotrexate (MTX) is the gold standard medical treatment for uncomplicated ectopic pregnancy - avoiding surgery in 70-95 % of cases in well-selected patients; methotrexate mechanism of action: folic acid antagonist → inhibition of dihydrofolate reductase → blockade of purine + pyrimidine synthesis → inhibition of cell proliferation → cytotoxicity on rapidly dividing trophoblastic cells → trophoblast necrosis → decrease in beta-hCG → resorption of GE; eligibility criteria for medical treatment with MTX (SOGC - Society of Obstetricians and Gynaecologists of Canada + ACOG 2023): stable hemodynamic status (no shock) + desire for conservative treatment + compliance with biological monitoring + prompt access to obstetric emergency if worsening + beta-hCG 2× ULN) + leukopenia (<3 × 10⁹/L) + thrombocytopenia (5,000 IU/L + embryonic cardiac activity + mass >3.5 cm + hemoperitoneum >300 mL + progesteronemia >20 nmol/L → in these situations → surgery preferred from the outset | Methotrexate treatment protocols: single-dose protocol (most widely used in North America - recommended by the SOGC): MTX 50 mg/m² IM as a single dose (calculated on body surface area - SC = Mosteller or DuBois formula) → beta-hCG measured at D1 (=D0 treatment) + D4 + D7 → success criterion: beta-hCG decrease of ≥15 % between D4 and D7 → then weekly monitoring until beta-hCG undetectable - 2nd dose of MTX : if decrease <15 % between D4 and D7 → 2nd injection of MTX 50 mg/m² → if 2 insufficient doses → surgery - success rate of single-dose protocol: 73-88 % (Barnhart 2003 meta-analysis) → slightly lower than multidose protocol but better tolerated + multidose protocol (MTX + leucovorin): MTX 1 mg/kg IM at D1 + D3 + D5 + D7 alternating with leucovorin 0.1 mg/kg IM at D2 + D4 + D6 + D8 → success rate: 87-93 % → more visits and adverse effects → reserved for higher beta-hCG values; MTX adverse effects: nausea + vomiting + stomatitis + abdominal pain (D3-J7: «separation pain» - trophoblastic separation - normal - not to be confused with rupture) + photosensitivity (avoid the sun × 2 weeks) + rarely: alopecia + transaminase elevation (transient) + interstitial lung disease (rare); instructions for patients on MTX: avoid folic acid during treatment (antagonizes the effect of MTX) + avoid NSAIDs and aspirin (reduce the efficacy of MTX) + avoid alcohol (additive hepatotoxicity) + abstain from sexual intercourse until resolution + effective contraception × 3 months thereafter (teratogenic risk of MTX - neural tube defects) + consult an emergency room if: severe abdominal pain + syncope + profuse bleeding |
| Surgical treatment — salpingectomy and salpingostomy Laparoscopy - laparotomy - ruptured GE - fertility |
Surgery remains the reference treatment for ruptured ectopic pregnancy and is the alternative to MTX in cases of contraindication or medical failure; surgical approaches: laparoscopy: standard approach in the vast majority of stable or unstable GE (if the team is trained) - advantages : fewer postoperative complications + faster recovery + rate of subsequent intrauterine pregnancy equivalent or superior to laparotomy (Hajenius 2007 meta-analysis - Cochrane) + laparotomy (Pfannenstiel or median laparotomy): indicated if : severe hemodynamic instability (shock + contraindication to pneumoperitoneum) + surgeon not trained in laparoscopy + bulky horn GE + morbid obesity + major adhesions + conversion to laparotomy if uncontrollable bleeding + deficient coagulation; two surgical options on the tube: salpingectomy (total removal of the tube): reference treatment - preferred indications: ruptured GE + recurrence of GE in the same tube + very damaged tube + healthy contralateral tube + desire for sterilization + very dilated tube - advantages : higher cure rate + no risk of residual GE + no need for beta-hCG monitoring + salpingostomy (linear tubal incision + removal of trophoblast - preservation of tube): indicated if: contralateral tube absent or pathological + desire for subsequent pregnancy + contralateral tube absent + essential to preserve tubal fertility - disadvantages: risk of residual GE (residual trophoblast - 5-20 % depending on series) → post-operative beta-hCG monitoring until normalization → if plateau → adjuvant MTX; intrauterine pregnancy rate after surgical treatment (DEMETER study - RCT - 2013) : salpingectomy vs salpingostomy in patients with healthy contralateral tube → cumulative intrauterine pregnancy rate at 2 years: 70 % vs 64 % → non-significant difference → salpingectomy is therefore preferable to salpingostomy if contralateral tube is healthy (less risk of residual GE without loss of fertility) | Management of ruptured GE - surgical emergency: immediate call of surgical + obstetric + anesthetic team → 2 wide venous lines + urgent workup (CBC + group + IAR + coagulation + creatinine) → vascular filling (NaCl 0,9 % or crystalloids) while awaiting surgery → blood transfusion if Hb <70 g/L (hemorrhagic shock) → urgent O-negative if group unknown → surgery WITHOUT delay - laparoscopy if trained team or immediate laparotomy if hemodynamic state too unstable → salpingectomy of ruptured tube → hemostasis + peritoneal lavage → drain if necessary → intensive care monitoring if shock → anti-D immunization : if Rh-negative patient → anti-D immunoglobulins (WinRho) 300 µg IM within 72h of surgery → prevent maternal-fetal alloimmunization (risk for future pregnancies); post-operative follow-up after surgery for unruptured GE: if salpingectomy → no mandatory beta-hCG monitoring (trophoblast removed with entire tube) → check at 1 week if doubt about complete excision + if salpingostomy → beta-hCG at D1 + D4 + D7 + weekly → if plateau or rise → adjuvant MTX → if persistence → new surgery + psychological care : loss of pregnancy - even ectopic - can generate perinatal grief + anxiety for future pregnancies → psychological support offered + referral to perinatal grief support resources (PANDA Quebec); resumption of contraception after GE: if desire for subsequent pregnancy → no hormonal contraception mandatory → wait for beta-hCG normalization + recommend deferring pregnancy for 3 months if MTX used + if no desire for pregnancy → effective contraception immediately (except IUD - wait for complete resolution and beta-hCG normalization) |
| Expectant management of GER Spontaneous resolution — decreasing beta-hCG — monitoring |
A proportion of ectopic pregnancies evolve spontaneously towards resorption without the need for active treatment - identification of these patients makes it possible to avoid exposure to MTX or surgery; candidates for expectant treatment (active monitoring without treatment): asymptomatic or minimally symptomatic patient + spontaneously decreasing beta-hCG (confirmed on 2 assays 48 h apart) + low initial beta-hCG (<1,000-1,500 IU/L - best results with betahCG <500 UI/L) + ectopic mass small or not visible on ETV + absence of hemoperitoneum + patient informed and compliant with follow-up + guaranteed access to a 24-hour obstetric emergency (in case of rupture) - success rate of expectant treatment : 48-88 % depending on series - highly variable depending on patient selection → best results if beta-hCG <200 IU/L decreasing + GE not visible on ETV; expectant monitoring protocol: beta-hCG at D0 + D2 + D4 + D7 + weekly until <5 IU/L + ETV at D7 + D14 → if beta-hCG rises or plateaus ( multidose MTX > single-dose MTX ≈ expectant → depending on patient selection + GE recurrence rate and subsequent fertility are comparable between the three non-surgical approaches | Information and support for patients on expectant treatment: clearly explain the risk of tubal rupture and the warning signs requiring urgent consultation of the emergency department: sudden intense abdominal pain ± syncope ± heavy bleeding + hand out a written information sheet with reconsultation criteria + obstetric emergency telephone number + insist on the absolute necessity of honoring all follow-up appointments (serial check-ups) - a non-compliant patient is not a candidate for expectant treatment; fertility after ectopic pregnancy: subsequent intrauterine pregnancy rate (all modalities combined): 50-80 % at 2 years depending on series + GE recurrence rate: 10-15 % after a 1st GE + 25-30 % after two GE + risk of recurrent GE on contralateral tube if history of bilateral salpingitis → fertility work-up recommended if no intrauterine pregnancy at 12 months (hysterosalpingography + FSH + LH + estradiol + AMH hormonal work-up + contralateral tube work-up) + GE and PMA techniques: if contralateral tube pathological (hydrosalpinx) after GE → bilateral salpingectomy recommended before IVF (hydrosalpinx reduces IVF success rates by 50 % through embryotoxicity of hydrosalpingian secretions) → advice in MAP center; prevention of GE recurrences: STI screening and treatment (Chlamydia trachomatis ++) + condom use + smoking cessation + endometriosis treatment if present + information on early signs of GE during subsequent pregnancies → early consultation from the first weeks of amenorrhea with a history of GE |
| Rare ectopic pregnancies — cornual, cervical, cesarean scar pregnancy CSP - Interstitial - Specialized Treatment |
Ectopic pregnancies of rare localization account for 5 % of GE but concentrate a disproportionate proportion of maternal morbidity and mortality due to their difficult diagnosis and high hemorrhagic risk; horn or interstitial pregnancy (intramural portion of the tube at the level of the uterine horn): prevalence: 2-4 % of GE + difficult ultrasound diagnosis (GE is partially surrounded by myometrium → falsely reassuring) → ETV diagnostic criteria (Ackermann et al.): gestational sac eccentric to endometrial cavity + surrounded by <5 mm myometrium + mobile mass + distinct from ovary → late rupture (10-14 SA) + catastrophic hemorrhage (highly vascularized myometrium) → mortality 2-2.5× higher than tubal GE → treatment: systemic MTX ± local injection guided under ETV + surgical coronal resection if failure or rupture → consultation in specialized center recommended + cervical pregnancy: implantation in the endocervical canal - very rare (1/10,000 pregnancies) - profuse bleeding + dilated cervix + gestational sac visible at the cervix on ETV → major bleeding risk during any curettage attempt → treatment: systemic MTX ± local intrasaccular injection + uterine artery embolization if hemorrhage + intracervical Foley balloon in case of bleeding - avoid excisional surgery from the outset; Caesarean Scar Pregnancy (CSP): incidence: 1/1,800-1/2,200 pregnancies - increasing with rising C-section rates in Quebec (C-section rate in Quebec: ~23 % in 2022-2023 according to MSSS data) - pathophysiology: implantation of blastocyst in scar niche (isthmocoele) - ETV diagnosis: gestational sac in anterior isthmus + thin endometrium separating sac from bladder → risk: placenta accreta/percreta → catastrophic hemorrhage + uterine rupture if evolving → treatment: MTX IM ± local injection + uterine artery embolization + guided aspiration under ETV monitoring + surgical resection by vaginal or abdominal route → follow-up by multidisciplinary team (obstetricians + interventional radiologists) + heterotopic pregnancy: simultaneous GE + GI - rare spontaneously but IVF multiplies the risk → difficult diagnosis (the GI can mask the GE) → treatment: local injection of KCl or MTX into the ectopic sac (systemic MTX CI because teratogenic risk for the GI) ± laparoscopic salpingectomy with preservation of the GI if possible → referral to specialized tertiary center | Management of rare GEs - general principles: any rare GE (cornuale + cervical + CSP + heterotopic) must be managed in a tertiary center with interventional imaging (interventional radiology + embolization) + a trained surgical team (obstetricians + vascular surgeons if necessary) + intensive care + an available blood bank; role of the family doctor in early detection of rare GEs: any woman with history of caesarean section + early pregnancy + pain + metrorrhagia → report history of caesarean section to obstetric team → early ETV + beta-hCG → if ectopic sac in isthmus → immediate transfer to tertiary center → do not attempt curettage or treatment without specialist advice; anti-D immunization in all GE: any Rh-negative patient with GE (regardless of treatment modality - medical + surgical + expectant) → anti-D immunoglobulins (WinRho SDF 300 µg IM) within 72 hours → prevent alloimmunization → protect future pregnancies; documentation and reporting: obstetrical vigilance data → maternal deaths from undiagnosed GE rupture are monitored by provincial and federal maternal mortality committees → early diagnosis and prompt management are the main levers for reducing maternal mortality from GE in Quebec. |
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Any woman of childbearing age with pelvic pain or metrorrhagia—do a pregnancy test first: Ectopic pregnancy is a major diagnostic pitfall in emergency gynecology. In the absence of a pregnancy test, it can be mistaken for appendicitis, ovarian torsion, salpingitis, or simply functional pain. The rule is simple: a positive urine pregnancy test in a woman with pelvic pain ± metrorrhagia equals ectopic pregnancy until proven otherwise, regardless of the contraception used. Quantitative serum beta-hCG and transvaginal ultrasound are the next steps, to be performed without delay.
Situations requiring urgent medical assessment
Sudden intense abdominal pain («stabbing») + tachycardia + hypotension + pallor + positive pregnancy test → Ruptured ectopic pregnancy with hemoperitoneum → Life-threatening surgical emergency → Call 911 + 2 IV lines + fluid resuscitation + urgent surgery (laparoscopy or laparotomy depending on available team).
Patient under watchful waiting or methotrexate + worsening pelvic pain + syncope or presyncope → Ruptured ectopic pregnancy → go to the emergency obstetrics department immediately → emergency surgery → do not wait for the next beta-hCG measurement.
Woman with history of C-section + early pregnancy + gestational sac at the anterior isthmus on transvaginal ultrasound → pregnancy on cesarean scar → immediate transfer to tertiary center → MTX ± embolization → do not perform outpatient curettage.
Positive beta-hCG + absence of intrauterine gestational sac on transvaginal ultrasound + beta-hCG > 2,000 IU/L → Ectopic pregnancy highly probable → immediate referral to gynecology-obstetrics → full workup + therapeutic decision (MTX or surgery) according to clinical context.
Consult at Clinique Omicron
Clinique Omicron doctors can provide the initial assessment for a painful or bleeding early pregnancy—pregnancy test, beta-hCG dosage, and rapid referral to the obstetric emergency department or a specialist based on the clinical presentation. In case of suspected ectopic pregnancy, immediate referral to the appropriate hospital center is required. For gynecological consultations and pregnancy follow-ups at our service points in Quebec, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not replace the advice of a doctor or obstetrician-gynecologist. Ectopic pregnancy is a potentially life-threatening medical emergency—any suggestive symptoms should be evaluated without delay at a healthcare facility.
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