Heterotopic pregnancy is the simultaneous presence of an intrauterine pregnancy and an ectopic pregnancy, most often tubal. It occurs in about 1 in 30,000 spontaneous pregnancies and up to 1 in 100 after assisted reproduction. It is often missed because the intrauterine pregnancy gives reassurance.

Risk factors: assisted reproduction, pelvic inflammatory disease, previous tubal surgery, ovulation induction.
Presents at 5 to 8 weeks.
Treatment must remove the ectopic pregnancy and spare the intrauterine pregnancy.

Patients with a known intrauterine pregnancy develop lower abdominal pain, vaginal bleeding or signs of intraperitoneal bleeding. Examination shows adnexal tenderness or peritonism.

Pain beyond that expected for early pregnancy.
Free fluid on scan.
Differential diagnosis: ruptured corpus luteum cyst, ovarian hyperstimulation, threatened miscarriage, appendicitis, ovarian torsion.
Complications: rupture, haemorrhage, loss of the intrauterine pregnancy, tubal loss, maternal death.

The principle is to remove the ectopic pregnancy and spare the intrauterine pregnancy; methotrexate is not given.

Supportive: two large-bore cannulae; Ringer's lactate 1 litre if unstable; blood available.
Pharmacological: no methotrexate, as it harms the intrauterine pregnancy; give progesterone support only if the intrauterine pregnancy follows assisted reproduction: micronised progesterone 400 mg vaginally twice daily to 12 weeks; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours).
Procedures: laparoscopic salpingectomy with minimal uterine manipulation; laparotomy if unstable.
Special groups: Rhesus negative women give anti-D immunoglobulin 250 IU IM within 72 hours.
Red flags: severe pain, shoulder tip pain, collapse, pulse above 100 per minute, falling haemoglobin.
Follow-up: ultrasound 1 week after surgery to confirm fetal viability; routine antenatal care; growth scan at 28 weeks.

Heterotopic Pregnancy

Overview

Clinical Features

Diagnosis

Management