|October 2002 · Vol. 14, No. 10
Heterotopic pregnancy: an emerging diagnostic challenge
Due in part to rising rates of in vitro fertilization, heterotopic pregnancy isn’t nearly as rare a condition as it was in times past. Here, the authors detail protocols for diagnosing and treating this challenging disorder.
Dr. Beyer is chief resident in the department of OBG, and Dr. Dumesic is professor in the department of OBG, division of reproductive endocrinology and the department of internal medicine, division of endocrinology at the Mayo Clinic in Rochester, Minn. Dr. Dumesic also serves on OBG Management’s Board of Editors.
The prevalence of heterotopic pregnancy has increased, due in part to in vitro fertilization techniques that transfer multiple embryos into the uterus.
An interstitial eccyesis can be distinguished from an angular pregnancy by the anatomical relationships of the round and ovarian ligaments to the fallopian tube.
Sonographic signs of interstitial heterotopic pregnancy include an eccentrically located echogenic mass surrounded by a thin myometrial rim, an interstitial line sign, and a myometrial bridge separating a suspected eccyesis from an intrauterine pregnancy.
The choice of surgical or medical treatment of heterotopic pregnancy depends upon the hemodynamic status of the patient and the expertise of the physician.
Physicians must closely observe during labor the hemodynamic status of women treated for interstitial or cornual heterotopic pregnancy, since the risk of uterine rupture is unknown.
Heterotopic pregnancy is a condition on the rise. In 1948, just 1 in 30,000 gravidas presented with this disorder, in which uterine and extrauterine gestations exist concomitantly.1 Today that rate is 1 in 3,800.2 And for women undergoing in vitro fertilization (IVF), the number is a startling 1 in 100.3
Why such a dramatic shift? In the general population of women, the increase may be due in part to a rise in pelvic inflammatory disease (PID),4 but other risk factors—including history of eccyesis, previous pelvic surgery, and congenital or acquired abnormalities of the uterine cavity—also may be contribute to the condition.3,5 But for IVF patients, the rise is largely attributable to the transfer of multiple embryos into the uterus.2,6 In fact, when more than 5 embryos are implanted, the risk of heterotopic pregnancy increases to 1 in 45.