Ectopic pregnancy is defined as the implantation and development of an embryo outside the uterus. Its incidence has increased over the past two decades.This data is strongly associated with an increased incidence of pelvic inflammatory disease and of assisted reproductive technology (ART) with multiple embryo transfers.
Interstitial pregnancy is defined as implantation
and development of an embryo in the proximal
portion of the fallopian tubes. Its incidence ranges
from 2 to 4% among ectopic pregnancies (
Treatment guidelines have not yet been established. Interstitial pregnancy is associated with a maternal mortality rate of 2-3% compared to 0.14% for tubal ectopic pregnancy,which makes it an urgent and dangerous condition. Interstitial ectopic pregnancy can develop in a highly vascularized mass up to the second trimester before rupture, which may cause severe hemorrhage.
Here we report two cases of tubal stump pregnancies
after bilateral salpingectomy and
A 33-year-old woman (gravida 4, para0) with no history of pelvic disease had a history of an appendectomy in childhood and a diagnostic laparoscopy for an ovarian cyst in 2003. She experienced three ectopic pregnancies: the first ended in partial left salpingectomy in 2004; the second, located in the right tube,was treated with methotrexate (MTX) in 2006; and the third was followed by a right total laparoscopic salpingectomy in 2009.In August 2010, the patient was treated with IVF, but did not become pregnant.
In November 2010 two frozen embryos were transfered. On the 14th day after embryo transfer, the serum beta-subunit of human chorionic gonadotrophin (beta-hCG) was 205 UI/mL; it rose to 732 UI/mL on the 16th day and 1633 UI/mL on the 19th day.
On the 22nd day after embryo transfer she was referred to our emergency department with complaints of lower abdominal pain and vaginal bleeding. Her vital signs were stable and a physical examination revealed diffuse lower abdominal tenderness with no signs of peritoneal irritation. Her hemoglobin level was 11.8 mg/dL. A transvaginal ultrasound (TVUS) revealed no intrauterine pregnancy sac and only a small accumulation of fluid in the Pouch of Douglas;her beta-hCG level was 1518 UI/mL. The patient was admitted to our gynecology ward and underwent TVUS and beta-hCG analyses every two days.
The day after admission to our ward a TVUS showed an accumulation of fluid in the cul-de-sac of 8.2x2.9 cm, and again no intrauterine pregnancy sac was detected in the uterine cavity. Serum hCG level splateaued as follows after embryo transfer: 2065 UI/mL (24<sup>th</sup> day), 2018 UI/mL (25th day), 1914 UI/mL (26<sup>th</sup> day), 1901 UI/mL (27<sup>th</sup> day), 2063 UI/mL (28<sup>th</sup> day), and 2173 UI/mL (29<sup>th</sup> day).
Finally, one month after embryo transfer TVUS
showed a 25 mm mass in the left tubal angle apparently
outside the myometrium,with no increase
in the amount of free fluid in the cul-de-sac (100
Pathologic examination of the excised tubal stump revealed trophoblastic tissue.
Cornual pregnancy with peripheral vascularization.
Left cornual pregnancy in sagittal, transversal, and coronal planes.
A 37-year-old woman with a history of bilateral laparoscopic salpingectomy for bilateralhydrosalpinx in 2004 underwent IVF; two embryos were transfered in April 2005. After 10 days, serum betra- HCG was 61UI/mL, which increased to231UI/ mL after 12 days, and 1408 UI/mL after 17 days.
One month after embryo transfer the patient was referred to our emergency department with severe abdominal pain and an episode of vomiting. Physical examination revealed stablevital signs, a painful abdomen, positive Blumberg’s sign, and ahemoglobin of 8.6 mg/dL. TVUS revealed a large amount of free fluid and blood clots in the left abdominal quadrant, a complex irregular mass of 5-6 cm in maximum diameter was also revealed in the right tubal stump.The patient underwent a laparoscopic right cornuostomy. The pathologic examination of the excised tubal stump revealed trophoblastic tissue.
The prevalence of ectopic pregnancy ranges from 6 to 16% in the general population. The overall incidence has increased dramatically in the last two decades due to an increase in pelvic inflammatory disease and the introduction of medical assisted procreation techniques.
Other risk factors are: previous ectopic pregnancy (15%), tubal diseases and surgery, Diethylstilbestrol (DES) exposure during pregnancy, intrauterine contraception, infertility, multiple sexual partners, and smoking.
Recently IVF treatments have become more frequent
due to increased maternal age at first pregnancy. ART represent an independent risk factor
for ectopic and heterotopic pregnancies. The rate
of heterotopic pregnancy (the simultaneous occurrence
of intrauterine and ectopic gestation) after
IVF is estimated to be as high as 0.3-1% (
Almost all ectopic pregnancies occur in the
fallopian tube (95%), with the distribution of
sites being: ampullary (76.9%), isthmic (12%),
and fimbrial (11.1%). Ectopic pregnancies are
ovarian (2%), interstitial or corneal (2%), and
the remaining are abdominal or cervical (
Risk factors for interstitial pregnancies are similar
to those for other tubal pregnancies (
The occurrence of interstitial pregnancy is estimated
to be 1:3600 for all pregnancies achieved with IVF
treatments. These pregnancies tend to be diagnosed
later than most other ectopic pregnancies, as interstitial
pregnancies can grow larger because the surrounding
myometrium is more expandable than within the
fallopian tube. Consequently, interstitial pregnancies
have an increased risk of rupture, and early diagnosis
is very important. In Bouyer’s study, almost one third
of cornual ectopic pregnancies have been diagnosed
after rupture with a significant hemoperitoneum. The
typical rupture of these ectopic pregnancies occurs after
9 weeks and as late as 20 weeks (
Diagnosis of interstitial pregnancy is quite difficult and based upon clinical findings, imaging studies (ultrasound), and laboratory tests (hCG).
A TVUS is the most useful test in determining
the location of an eectopic pregnancy, despite
some studies that describe the use of MRI in diagnosing
a pregnancy in a rudimentary horn (
TVUS is very important for differential diagnosis
among ectopic pregnancy sites.US diagnosis
of cervical pregnancy requires the following criteria:
enlargement of the cervix and uterus, diffuse
amorphous intrauterine echoes, and no intrauterine
pregnancy. The pregnancy sac must be below the
internal cervical os, the cervical canal must be dilated,
and the cervix must have a barrel shape (
US findings are useful to diagnose if an ovarian pregnancy can be a walled cystic mass within or adjacent to an ovary; however, Doppler US can not reliably distinguish between an ovarian implantation and a corpus luteum.
Three TVUS criteria are needed to diagnose an
abdominal pregnancy, according to Studdiford in
1942: first, the absence of pathologic findings in
the fallopian tubes; second, the absence of any
uteroperitonel fistula; third, a pregnancy related to
the peritoneal surface must be present to eliminate
the possibility of a secondary implantation (
It can be difficult to differentiate between a
spontaneous abortion in progress, cervico-isthmic
pregnancy, and implantation within a cesarean scar
US findings highly suggesting an interstitial ectopic
pregnancy are: the identification of an echogenic
line between the gestational sac and the endometrial
cavity and an empty uterine cavity with
a gestational sac located outside the endometrial
cavity with a myometrium less than 5 mm thick
It is very important to obtain an accurate medical history in order to identify women at risk of interstitial pregnancy, i.e. those who have undergone previous salpingectomy and a recent IVF.
This article underlines the importance of total salpingectomy and accurate cauterization of the tubal stump in patients undergoing surgery for ectopic pregnancy in the fallopian tube in order to avoid the risk of a consequent interstitial pregnancy. Particular attention must be taken in women undergoing IVF treatments.
Uterine rupture in pregnancies following salpingectomy
for corneal pregnancy has been described
Management of interstitial pregnancy varies
widely in the literature (
Both of our patients were treated with surgery; the second patient particularly underwent surgery in order to avoid a second ectopic pregnancy in the same position after further IVF treatment.
In conclusion, after IVF treatment, and particularly in patients with prior bilateral salpingectomy, special attention to interstitial pregnancy is warranted, as it remains a life-threatening condition. Surgery remains the mainstay treatment among patients who have undergone a previous partial salpingectomy.