Heterotopic Pregnancy (HP)
Definition - What does Heterotopic Pregnancy (HP) mean?
A heterotopic pregnancy (HP) occurs when two (or more) pregnancies occur simultaneously with separate sites of implantation, with one of the pregnancies being ectopic (EP) or not within the uterus. Implantation sites outside of the uterus may include the fallopian tube, cervix and cesarean delivery scar.
FertilitySmarts explains Heterotopic Pregnancy (HP)
Heterotopic pregnancies are estimated to occur in 1 in 10,000 to 30,000 pregnancies. It is rare for these pregnancies to occur in women who spontaneously conceived through intercourse, but there is a slightly higher (1-3%) risk for women who have been treated with assisted reproductive technology (ART) such as in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT). For this reason, women treated with ART typically undergo routine early ultrasound screening for this condition.
Risk factors for HP include a history of:
- Previous ectopic pregnancy
- Pelvic inflammatory disease (PID),
- Reconstructive tubal surgery
Symptoms are similar to those of an EP and include spotting, dizziness, and cramping. Around 50% of HP cases are diagnosed after the rupturing of the ectopic pregnancy, requiring immediate medical attention.
Pregnancies that occur outside of the uterus are non-viable and can be fatal to the mother if left untreated. That said, more than half of HP cases where implantation occurs in the uterus result in successful deliveries.