Tubal Ectopic Pregnancy

Tubal ectopic pregnancy is implantation of a pregnancy in the fallopian tube, most commonly the ampulla, caused by tubal damage from infection, surgery or smoking. It makes up 95 percent of ectopic pregnancies and is a major cause of first trimester maternal death through tubal rupture.

• Ampulla about 70 percent, isthmus 12 percent, fimbria 11 percent.
• Risk factors: pelvic inflammatory disease, previous tubal surgery, previous ectopic, assisted reproduction, intrauterine contraceptive device.
• Conservative treatment is possible when diagnosed early.

Patients have 6 to 8 weeks of amenorrhoea, unilateral lower abdominal pain and spotting or bleeding. The adnexa are tender, and cervical movement causes pain.

• Pain may precede bleeding.
• Rupture causes sudden severe pain, shoulder tip pain and collapse.
• Differential diagnosis: threatened miscarriage, ruptured corpus luteum, appendicitis, ovarian torsion, pelvic inflammatory disease, urinary tract infection.
• Complications: tubal rupture, haemoperitoneum, shock, tubal loss, infertility, recurrence.

The approach is transvaginal ultrasound with hCG.

• Ultrasound: empty uterus, adnexal mass (tubal ring sign), free fluid.
• Serum hCG: above 1500 IU/L with an empty uterus is strongly suggestive; slow rise or plateau supports the diagnosis.
• Full blood count, blood group and Rhesus status, urea and creatinine, liver enzymes before methotrexate.
• Laparoscopy confirms the diagnosis when doubt persists.

Treatment is surgery for unstable or high risk patients, and methotrexate or expectant care for selected stable patients.

• Supportive: IV access, Ringer's lactate 1 litre rapidly, cross-match 4 units, transfusion for shock.
• Pharmacological: methotrexate 50 mg/m2 IM single dose day 1 if stable, hCG below 5000 IU/L, no fetal cardiac activity, mass below 35 mm, normal blood count, liver and renal tests; hCG on days 4 and 7; repeat dose if fall is below 15 percent; weekly hCG to negative; no NSAIDs, alcohol or sun exposure; contraception for 3 months; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours).
• Procedures: laparoscopic salpingectomy when the other tube is healthy; salpingotomy when the other tube is damaged and fertility is wanted, with weekly hCG after; laparotomy if unstable.
• Special groups: Rhesus negative women give anti-D immunoglobulin 250 IU IM within 72 hours.
• Red flags: shoulder tip pain, syncope, pulse above 100 per minute, falling blood pressure, severe pain after methotrexate.
• Follow-up: weekly hCG until negative; early scan in the next pregnancy; counsel on recurrence risk of 10 to 15 percent.