Triplet Heterotopic Pregnancy After Gonadotropin Stimulation
Heterotopic pregnancy has been traditionally considered a rare event; however, with the use of assisted reproductive technology, the incidence of heterotopic pregnancies is increasing. Diagnosing a heterotopic pregnancy can be challenging. This report describes a 30-year-old female at 11 weeks' gestation with an intrauterine twin pregnancy after gonadotropin stimulation and intrauterine insemination who presented complaining of left lower quadrant abdominal pain with constipation and cramps. The patient was empirically treated for diverticulitis but failed to respond to therapy. A heterotopic triplet pregnancy was ultimately diagnosed at laparoscopy. Heterotopic pregnancy must be considered in the differential diagnosis of abdominal pain in the first trimester, especially in patients who conceived by means of assisted reproductive technology. Surgical treatment is the most frequently used method of treatment.

Heterotopic pregnancy is a potentially fatal condition in which gestation occurs at two or more implantation sites: an intrauterine site and one or more extrauterine sites. It was first described in 1708 by Duverney, who reported the finding at an autopsy of a patient who died as a result of a ruptured ectopic pregnancy but also had a simultaneous intrauterine pregnancy. Heterotopic pregnancy has been reported to occur spontaneously in 1 in 30,000 pregnancies; however, with the use of assisted reproductive technology, the rate may be as high as 1 in 100 pregnancies.

Several case reports have described intrauterine twin pregnancies with concurrent heterotopic triplets or quadruplets in the early part of the first trimester. Here, we describe a triplet heterotopic pregnancy with intrauterine twins diagnosed in the late first trimester at laparoscopy after empiric treatment for diverticulitis failed to relieve the patient's symptoms.