Heterotopic pregnancy: is it really a rare event? The importance to exclude it not only after in vitro fertilization but also in case of spontaneous conception.

3 05 2010

To the Editor:

We read with interest the paper by Kamath et al. (1) which reported a case of ovarian heterotopic pregnancy after an in vitro fertilization (IVF) cycle.

The case is very informative and of immense clinical value. Moreover, we had a particular case of a spontaneous heterotopic pregnancy in a 34-year-old woman referred to our unit at 6 weeks of gestation without risk factors and without any clinical manifestation, making the diagnosis really difficult. In this regard, it is probably necessary to outline the importance of considering a heterotopic pregnancy also after spontaneous conception and in asymptomatic patients.

Heterotopic pregnancy, in fact, is a rare clinical condition in which intrauterine and extra-uterine pregnancies occur at the same time, with a prevalence of 1/30,000 in spontaneous conception and increased incidence of 1:100-500 gestations after assisted reproduction techniques (ARTs) (2).

Because it may be a life-threatening condition that can be easily missed with the diagnosis being overlooked, we must always exclude the presence of an ectopic gestational sac in the early phases of pregnancy. A high index of suspicion is needed in women with risk factors such as previous ectopic pregnancy, history of tubal surgery, tubal sterilization, sexually transmitted infection, tubal infection, pelvic adhesions, intrauterine device, the use of progestin-only birth control pills and implanted progestin contraception methods, cigarette smoking and in utero exposure to diethylstilbestrol (3).

No risk factor was present in our patient and no symptom was reported. Furthermore, at admission a careful transvaginal ultrasound assessment was performed. Even though ultrasonography does not have a high sensitivity for the early diagnosis of heterotopic pregnancy (about 56% at 6 weeks of gestation) (4), a diagnosis of a heterotopic pregnancy was made for the detection of a single intrauterine gestational sac with a live embryo, corresponding to about 6 weeks of gestation and the presence in left adnexal area of another gestational sac with a vital embryo corresponding to 6 weeks.

Laparoscopic removal of ectopic pregnancy was proposed after careful counseling because its management is still debated. A total left salpingectomy was performed laparoscopically with success.
Our clinical experience underlines that the early detection of the heterotopic pregnancy is crucial for its successful treatment and management. Our patient had a single viable ongoing intrauterine pregnancy with a final favorable outcome, and avoided a potentially fatal evolution (5).

Giuseppe Maria Maruotti, Ph.D.a
Laura Sarno, M.D.a
Tiziana Russo, Ph.D.b
Angelo Sirico, M.D..a
Pasquale Martinelli, M.D..a

aHigh Risk Pregnancy Unit
Department of Obstetrics and Gynecology
University Federico II
Naples, Italy
bPrenatal Diagnosis Unit
Department of Obstetrics & Gynecology
University “Magna Grecia”
Catanzaro, Italy

1. Kamath MS, Aleyamma TK, Muthukumar K, Kumar RM, George K. A rare case report: ovarian heterotopic pregnancy after in vitro fertilization. Fertil Steril. 2010 Mar 31. [Epub ahead of print]

2. Donadio NF, Donadio N, Martins PT, Cambiaghi Cde G. Heterotopic gestation: diagnostic possibility after in vitro fertilization. A case report. Rev Bras Ginecol Obstet 2008;30:466-9.

3. Lavanya R, Deepika K, Patil M. Succesful pregnancy following medical management of hetrotopic pregnancy. J Hum Reprod Sci 2009;2:35.

4. Dundar L, Tutuncu E, Mungen YZ, Yergok. Heterotopic pregnancy: Tubal ectopic pregnancy and monochorionic monoamniotic twin pregnancy: A case report. Perinatal Journal 2006;14:96-100.

5. Barrenetxea G, Barinaga-Rementeria L, Lopez de Larruzea A, Agirregoikoa JA, Mandiola M, Carbonero K. Heterotopic pregnancy: two cases and a comparative review. Fert Steril 2007;87:12-25.

Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2010.05.001

The Authors Respond:

We would like to thank Professor Maruotti and his team for their comments and the appreciation they have shown. They have reported a case of spontaneous heterotopic tubal pregnancy occurring in a woman with no complaints or risk factors, who was referred to their unit at 6 weeks gestation. The diagnosis was made on a routine transvaginal ultrasound after admission. They have rightly pointed out that in the presence of risk factors one must always exclude an ectopic pregnancy and trans-vaginal ultrasound in early gestation is indispensable.

We have reported a case of heterotopic ovarian pregnancy, which is indeed rare. With the introduction of assisted reproductive technology (ART) the incidence of heterotopic pregnancies is now 1:100-500. However heterotopic ovarian pregnancies still remain at 2.3% of all heterotopic pregnancies.

Our case report highlights the following:

1) Heterotopic pregnancies are more common following IVF, especially when more than one embryo has been replaced.

2) The index of suspicion needs to be raised when a singleton intrauterine pregnancy is associated with high beta hCG levels.

3) Ovarian enlargement is common following IVF and can hamper diagnosis.

4) Heterotopic ovarian pregnancies are still uncommon.

One of the guiding principles taught in medical school is to always consider common conditions first. If this does not fit the pattern one thinks of uncommon presentations of common conditions and only then of rare conditions. This principle streamlines the approach to clinical situations.

Although routine versus selective use of early ultrasound does have benefits in terms of detecting multiple pregnancy and confirming dates, it is still not regular practice (1). Even with an increased awareness of the possibility of a heterotopic pregnancy diagnosis by early transvaginal ultrasound is difficult, with the sensitivity of the procedure being as low as 26% (2). With a risk of 1: 30,000 in a general population the benefits of routinely evaluating all pregnant women in early gestation for a heterotopic pregnancy needs to be very carefully weighed.

Korula George, M.D., M.R.A.C.O.G.
Mohan S Kamath, M.S., D.N.B.
T.K. Aleyamma, M.D.,D.N.B.
Christian Medical College Hospital
Vellore, India

1. Whitworth M, Bricker L, Neilson JP, Dowswell T. Ultrasound for fetal assessment in early pregnancy. Cochrane Database of Systematic Reviews 2010 ;( 4):CD007058.

2. Barrenetxea G, Barinaga – Rementeria L, Lopez de Larruzea A, Agirregoikoa JA, Mandiola M, Carbonero K. Heterotopic pregnancy: two cases and a comparative review. Fertil Steril 2007; 87:417e9-417e15.

Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2010.05.002




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