Heterotopic Pregnancy: A Risk With Fertility Drugs?

April 15, 2006

How common is “dual” (ectopic and intrauterine) pregnancy in women who usefertility drugs?

How common is "dual" (ectopic and intrauterine) pregnancy in women who usefertility drugs?

The first documented case of heterotopic (combined intrauterine andectopic) pregnancy was diagnosed at autopsy and reported by Duverneyin 1761. Some researchers have determined that the incidence ofheterotopic pregnancies ranges from 1 in 10,000 births to 1 in 30,000.Other experts-using different statistical methods and assumptions-have found that the incidence ranges from 1 in 3889 births to 1 in 7963.1,2

The risk of heterotopic pregnancy is much greater for patients who conceiveby in vitro fertilization or gamete intrafallopian transfer. Between 0.6% and5.6% of in vitro pregnancies have been heterotopic.3 Given that this method ofconception involves the transfer of multiple embryos, an increase in heterotopicpregnancies is to be expected.

Pregnancies that result from ovulation induction are also more likely tobe ectopic or heterotopic than those that result from spontaneous ovulation. Between1.1% and 4.6% of conceptions that follow gonadotropin administrationare ectopic.4 Whether hyperstimulation plays a role in causing tubal pregnancyis somewhat controversial. The exact incidence of heterotopic pregnancy inpatients who have undergone hyperstimulation is unknown, but it is probablyabout 10-fold higher than that seen in patients who conceive naturally.

-Thomas G. Stovall, MD
  Professor, Obstetrics and Gynecology
  University of Tennessee


REFERENCES:1. Trotnow S, Kniewald T, Hunlich T, et al. Experiences with the first 100 consecutive pregnancies achievedafter in vitro fertilization and embryo transfer at the University Women’s Hospital in Erlangen. Arch Gynecol.1985;237:57-66.
2. Yuzpe AA, Brown SE, Casper RF, et al. Rates and outcome of pregnancies achieved in the first four yearsof an in-vitro fertilization program. CMAJ. 1989; 140:167-172.
3. Molloy D, Deambrosis W, Keeping D, et al. Multiple-sited (heterotopic) pregnancy after in vitro fertilizationand gamete intrafallopian transfer. Fertil Steril. 1990;53:1068-1071.
4. Oelsner G, Menashe Y, Tur-Kaspa I, et al. The role of gonadotropins in the etiology of ectopic pregnancy.Fertil Steril. 1989;52:514-516.