Heterotopic pregnancy

Definition

• A heterotopic pregnancy is the simultaneous presence of an intrauterine and an extrauterine pregnancy.

Classification

Heterotopic and abdominal pregnancy

• A heterotopic pregnancy, which is a simultaneous intrauterine and extrauterine pregnancy, occurs significantly more often after assisted reproduction.
• For diagnosing a heterotopic pregnancy, beta-hCG is not diagnostically conclusive.

Occurrence & epidemiology

Epidemiology

• It is rare; reported figures are about 1 in 10,000 to 30,000 pregnancies, and it is more common after ovarian stimulation or assisted reproduction.
• Its frequency has increased over recent decades, which is attributed to the wider use of ovarian stimulation and assisted reproduction; after natural conception it is rare.

Aetiopathogenesis

Aetiology and risk factors

• Risk factors largely correspond to those of ectopic pregnancy, for example smoking, previous ectopic pregnancy, pelvic inflammatory disease, sexually transmitted infections (especially chlamydia) and endometriosis.

Clinical features

Clinical features and complications

• Diagnosis is usually made in the first trimester (median 8 weeks); the commonest complication is tubal rupture.
• The intrauterine pregnancy can mask the extrauterine one and thus delay the diagnosis.

Diagnosis

• Transvaginal ultrasound shows both the intrauterine and the extrauterine pregnancy in about 88.9% of cases; diagnosis relies on a complete ultrasound examination of the uterus and adnexa.

Keep learning in the app

Further reading (selection)

1. Medicina (Kaunas) 2020: Spontaneous Heterotopic Pregnancy with Unaffected Intrauterine Pregnancy: Systematic Review of Clinical Outcomes (PMC, open access)
2. MSD Manual Professional Edition: Ectopic Pregnancy (Pregnancy of Unknown Location)
3. DocCheck Flexikon, Zervixgravidität

Cross-references