Keywords 

Ovarian Ectopic Pregnancy, Interval Tubal Ligation.

Introduction

Ectopic tubal gestation following tubal ligation accounts for 12% of all ectopic pregnancies1. Ovarian ectopic gestation is very rare (0.5%)2 and there are very few reports of ovarian ectopic pregnancy following tubal ligation. We report a case of primary ovarian ectopic pregnancy which occurred three years after bilateral tubal ligation.

Case Report

A 29 years old lady P2+0 presented to our emergency in the Department of Obstetrics & Gynaecology of Bankura Sammilani Medical College & Hospital, Bankura with the chief complain of lower abdominal pain and vomiting for 3 days.

On admission, she was alert, conscious, cooperative and apparently haemodynamically stable. Her BP was 110/76 mmHg, pulse rate 80/min, temperature normal, with moderate amount of pallor.

Her menstrual cycle was regular. There was no history of missed period.

She had history of two vaginal deliveries. Last child birth was 5 years back and bilateral tubal ligation was done 3 years back.

On per abdominal examination abdomen was tensed with tenderness in right iliac fossa. Per vaginal examination showed bulky uterus with parous os, tenderness in right fornix with an adnexal mass. Cervical motion tenderness was positive. No active bleeding per vagina seen.

Urine for pregnancy test was positive. Before operation Haemoglobin level was 7.8gm%. Urgent ultrasonography report revealed right sided tubo-ovarian mass 4.6cm.×4.2cm. in size. Free fluid in abdomen ++ extending upto hepatorenal pouch. Uterine cavity was empty.

A diagnosis of ruptured ectopic pregnancy was made. The patient was prepared for Urgent Exploratory Laparotomy and sent to operation theatre immediately. Simultaneously resuscitation was going on to correct the shock. Under general anaesthesia abdomen was opened. After opening abdomen, haemoperitoneum (approx. 500ml) detected. Uterus was bulky. A right sided haemorrhagic blackish irregular nodular mass 5cm.×4cm.×4cm. was seen embedded within the right ovary and connected to the uterus by the uteroovarian ligament. Both the tubes including the fimbrial ends with ostia were intact with previous ligation sites. Left sided ovary was healthy Fig.1.

Right sided salpingo-oophorectomy was done. Haemostasis secured. Religation of left sided fallopian tube was done. Abdomen was closed in layers after peritoneal wash and taking count of the instruments & the mops.

Specimen of right sided ovary with parts of both the fallopian tubes was sent for histopathological examination.

Post operative period was uneventful. Two units of whole blood were transfused. Patient was discharged in satisfactory condition after stitch removal.

Histological Examination

Histological examination of the ovary showed chorionic villi embedded in the ovarian parenchymal tissue with surrounding haemorrhage, consistent with ovarian ectopic gestation Fig.2. The fallopian tubes were oedematous and congested, the lumens were filled with fresh blood and there was no evidence of gestational tissue. So, the features were suggestive of ovarian ectopic gestation.

Discussion

Ectopic gestation after tubal ligation occurs due to recanalization of the fallopian tube or formation of a tuboperitoneal fistula. Spermatozoa may pass through the ligation site, but the fertilized ovum fails to go through, so implantation occurs in the distal tubal segment3,4. Ovarian pregnancy, as such, is very rare (0.5%)2 with a reported incidence of 1/7000 - 1/40,000 pregnancies5,6 while it is generally seen in cases following intrauterine contraceptive device (IUCD) insertion. Because IUCDs protect the endometrium and to a lesser extent, the proximal oviducts from implantation, it was expected that when IUCDs were introduced, future reports of extrauterine pregnancies might show an increased rate of ovarian involvement. Data from the Cooperative Statistical Program of the Population Council show that 1 of every 9 ectopic pregnancies among IUCD users is an ovarian pregnancy2. So far, only a few cases of ovarian pregnancy following tubal ligation have been reported as per the literature survey. A case by Wittich, AC in 20047 has reported that the ovarian ectopic pregnancy occurring following postpartum tubal ligation as the tubes are oedematous, friable and congested resulting in incomplete occlusion of tubes. But, in our case, ovarian ectopic pregnancy occurring following interval tubal ligation without any history of amenorrhea, is, in fact, quite rare.

The embedding may occur intrafollicular or extrafollicular. Only 15% of cases of ovarian pregnancy are intrafollicular in origin2. In an intrafollicular ovarian pregnancy, the second stage of meiosis, ovum capacitation and fertilization each occur within the follicle. In an intrafollicular pregnancy, a well-preserved corpus luteum can be identified in the wall of the gestational sac. Four other “criteria presented by Spiegelberg” for identifying an intrafollicular pregnancy are 1) that the tube, including the fimbria ovarica, is intact and is clearly separate from the ovary; 2) that the gestational sac definitely occupies the normal position of the ovary; 3) that the sac is connected to the uterus by the uteroovarian ligament; and 4) that ovarian tissue is unquestionably demonstrated in the wall of the sac.

Early diagnosis of an ovarian pregnancy, of all the diagnoses relating to extrauterine gestations, is perhaps the most difficult. The classic presentation of pain and uterine bleeding with the finding of an adnexal mass is present in only 14% of patients with ectopic pregnancy2. Even when present, these classic signs and symptoms are not entirely specific for ectopic pregnancy. Persistent pelvic pain alone is the most frequent clinical manifestation of an ovarian gestation. Although an adnexal mass is palpable in as many as 60% of ovarian pregnancies2, the mass is frequently confused with a leaking corpus luteum haematoma. Incomplete spontaneous abortion with a leaking corpus luteum haematoma mimics an ovarian pregnancy.

All of the test criteria used for diagnosing a tubal pregnancy are helpful in diagnosing a primary ovarian pregnancy. Critical evaluation of all of the diagnostic studies, particularly the highly sensitive and rapid ß-hCG immunoassay and transvaginal ultrasonography, is necessary in making the diagnosis. When the ß-hCG is positive, ultrasonography shows no intrauterine gestational sac, and free fluid exists in the peritoneal cavity; a laparoscopy, as a diagnostic tool, should be performed to confirm or refute a diagnosis of suspected ovarian pregnancy if the condition of the patient permits.

The highly sensitive ß-hCG immunoassay can confirm the presence of a gestational process, but the ß-hCG level does not help to precisely locate the gestation. A tubal pregnancy can easily be ruled out with laparoscopy, but an ovarian pregnancy is sometimes difficult to differentiate from a leaking corpus luteum haematoma by gross appearance. Ultrasonography can be helpful, but only in advanced ovarian pregnancy will the ultrasound image show a discrete gestational sac, therefore confirming an ovarian pregnancy.

A safe approach is to proceed with localized surgical resection of the bleeding mass with conservation of the ovary, if possible. Only rarely is the haemorrhage so profuse that oophorectomy is required to control bleeding. Even if the last trophoblastic villus cannot be removed in the ovarian resection, the ovary should be preserved. Any remaining trophoblastic tissue will usually degenerate rapidly or respond to postoperative Methotrexate therapy and therefore should produce no long-standing clinical problem2. In our case, right sided salpingo-oophorectomy was done as there was haemorrhage from the mass and most of the ovarian tissue was damaged. Serum ß-hCG level became normal after two weeks in post operative period.

Conclusion

We would like to emphasize the fact that, though ectopic tubal or ovarian gestation are rare after tubal ligation, the clinician has to consider this possibility when the patient with history of tubal ligation comes with typical or atypical signs and symptoms of ectopic gestation following history of amenorrhea or even without any history of amenorrhoea.

The benefits derived from the early diagnosis of an ectopic pregnancy include the potential use of medical and conservative surgical procedures that optimize future fertility and conservation of the ovary in case of ovarian ectopic pregnancy. Early diagnosis may also preclude ectopic pregnancy rupture and therefore result in lower patient morbidity and mortality. Women undergoing tubal ligation should be educated about its possibility, so that early interventions can be taken to minimize complications.

References

1. Chakravarti S, Shardlow J. Tubal pregnancy after sterilisation. Br J Obstet Gynaecol 1975;82:58-60.
2. Rock JA , Jones III HW . Te Linde’s Operative Gynecology 10 th edition , Lippincott,Williams & Wilkins 2008 : pp 817-818.
3. Davis MR. Recurrent ectopic pregnancy after tubal sterilization. Obstet Gynecol 1986;68:44S 45S.
4. Stock RJ, Nelson KJ. Ectopic pregnancy subsequent to sterilization: histologic evaluation and clinical implications. Fertil Steril 1984;42:211-5.
5. Itoh H, Ishihara A, Koita H, Hatakeyama K, Seguchi T, Akiyama Y, Et al. Ovarian pregnancy: report of four cases and review of the literature. Pathol Int 2003;53:806-9.
6. Salas Valien JS, Reyero Alvarez MP, González Morán MA, García Merayo M, Nieves Díez C. [Ectopic ovarian pregnancy]. An Med Interna 1995;12:192-4.
7. Wittich AC. Primary Ovarian Pregnancy after postpartum bilateral tubal ligation: a case report. J Reprod Med 2004,49:759-61.