Ectopic Pregnancy: A Clinical Casebook

13. Ovarian Ectopic Pregnancy

Warren J. HuberIII  and Gary N. Frishman 

(1)

Women and Infants Hospital, 101 Dudley St, 02905 Providence, RI, USA

Warren J. HuberIII (Corresponding author)

Email: whuber@wihri.org

Gary N. Frishman

Email: Gary.Frishman@Brown.edu

Keywords

Ectopic pregnancyEctopicTubal pregnancyPrimary ovarian ectopicOvarian pregnancyRuptured ectopicMethotrexateTransvaginal ultrasound

Abbreviations

hCG

Human chorionic gonadotropin

OEP

Ovarian ectopic pregnancy

KCl

Potassium chloride

Case Study

A 37-year-old gravida 3, para 1 woman with a 7-week pregnancy presented for a routine viability ultrasound . The pregnancy resulted from a natural cycle intrauterine insemination performed for male factor infertility. Initial serum human chorionic gonadotropin (hCG) levels rose appropriately with the hCG level at time of ultrasound being 12,074 mIU/ml. On physical examination, the patient was asymptomatic and denied vaginal bleeding or pain. Transvaginal ultrasound revealed a normal appearing uterus with no sonographic evidence of an intrauterine gestation. The right adnexa was unremarkable. The left ovary had an intraovarian gestational sac measuring 2.1 × 1.9 × 2.4 cm containing a yolk sac and fetal pole (Fig. 13.1). The fetal heart rate was 125 beats/min (Fig. 13.2). Gestational age was calculated to be 6 weeks 1 day. A corpus luteum was also visible within the left ovary, adjacent to and distinct from the pregnancy. No free fluid was detected in the cul-de-sac [1].

A321655_1_En_13_Fig1_HTML.gif

Fig. 13.1

Transvaginal ultrasound of the left ovary revealed an intraovarian gestational sac with yolk sac adjacent to suspected corpus luteum. (Reproduced with permission from The Journal of Minimally Invasive Gynecology)

A321655_1_En_13_Fig2_HTML.gif

Fig. 13.2

Transvaginal ultrasound of the left ovary revealed an intraovarian gestational sac with detectable fetal heart rate with M-mode. (Reproduced with permission from The Journal of Minimally Invasive Gynecology)

My Management

a.

b.

c.

Diagnosis/Assessment

Implantation of a pregnancy outside of the endometrium, collectively referred to as an ectopic pregnancy, complicates approximately 2 % of pregnancies [2]. Nontubal ectopics are especially concerning since they may present late and/or be more vascularized with a higher risk of life threatening bleeding if they rupture. Primary ovarian ectopic pregnancy (OEP) is a rare form of ectopic pregnancy, estimated to occur in 3.6 % of all ectopic pregnancies [3]. The etiology of primary OEP remains unknown and can occur in the absence of risk factors. Embryo migration from the fallopian tube has been described as a potential mechanism of an ovarian ectopic [4]. A review by Joseph and Irvine reported that contraceptive intrauterine devices and assisted reproductive technology each accounted for roughly 20 % of all ovarian ectopic pregnancies [5].

Since many women with ectopic pregnancies are asymptomatic, early diagnosis of ectopic pregnancy, especially nontubal ectopic pregnancies, requires a high index of suspicion and a skilled ultrasonographer. Abdominal pain and vaginal bleeding are presenting symptoms of an ectopic pregnancy regardless of the location, making it difficult to distinguish an OEP from both tubal and nontubal pregnancies. Failure to diagnose an OEP can be catastrophic due to potential rupture of the ovary and subsequent internal bleeding , dramatically increasing the likelihood of needing major surgical intervention alongside loss of the ovary. Indeed, ruptured ectopics may present with an acute abdomen, shoulder pain (secondary to diaphragmatic irritation), and even hypovolemic shock secondary to the hemoperitoneum [5].

The classic diagnosis of an OEP was confirmed surgically by the original four Spiegelberg criteria (1878): (1) the ipsilateral fallopian tube and fimbria are intact and separate from the ovary, (2) the gestational sac is in the normal position of the ovary, (3) the gestational sac is connected to the uterus by the ovarian ligament, and (4) ovarian tissue must be attached to the specimen and within the gestational sac. Although the classic definitive diagnosis of an OEP depends on these histopathologic findings obtained surgically [6], advances in transvaginal sonography have led it to become a key diagnostic tool in ovarian, as well as other, ectopic pregnancies. Ovarian pregnancies classically appear as a hypoechoic cyst on or within the ovary and are characterized by a wide echogenic (hyperechoic) outside ring [7]. A yolk sac or fetal pole is less commonly seen. Interestingly, approximately 70 % of ovarian ectopic pregnancies are not diagnosed, instead being mistaken as a ruptured corpus luteum or a hemorrhagic cyst due to their similar clinical features [6]. In the case presented here, OEP was diagnosed by sonographic evidence of a gestational sac and fetal pole with a measurable heart rate within the left ovary.

Management

Management strategies used for OEPs are similar to those used in tubal pregnancies [5]. Hemodynamic stabilization with immediate surgical management is appropriate with clinical features suggestive of a ruptured ectopic pregnancy in the unstable patient. The surgical approach is both patient- and surgeon-dependent, consisting of laparoscopy and/or laparotomy with the ultimate goals of removal of ectopic pregnancy tissue, achieving hemostasis , and preservation of healthy ovarian tissue [8]. Historically, OEPs were treated via removal of the entire ovary or by wedge resection attempting to conserve some remaining healthy ovarian tissue [9]. Postoperative methotrexate may be considered with concern for residual trophoblastic tissue following surgery in appropriate patients [5].

Primary medical treatment can be considered in hemodynamically stable patients. Although medical management of OEP with systemic methotrexate has been successful [10], concern for treatment failure requiring emergent surgery exists [11]. This is especially true with the presence of a fetal heart suggesting an advanced pregnancy. Administering intramuscular (IM) medical therapy may avoid surgical intervention; however, monitoring for resolution of the process may take a week or longer and this can be stressful for both provider and patient.

Evolution of care now often permits an earlier diagnosis, which allows for consideration of conservative nonsurgical management [1]. Local instillation of methotrexate, KCl, or hyperosmolar glucose under ultrasound guidance provides many advantages including limited systemic toxicity, higher concentration of chemotherapy at the ectopic site, and direct visualization of immediate ectopic disruption [12]. Treatment of OEP by transvaginal ultrasound-guided aspiration of the pregnancy followed by local administration of methotrexate, may be especially valuable in the presence of a fetal heart. Advantages are a shorter interval to establish treatment efficacy (with immediate cessation of fetal heart activity) alongside still avoiding a surgical approach which, independent of the additional morbidity associated with a laparoscopy or laparotomy, might culminate in removing the ovary [1].

Outcome

Following a discussion of treatment options, with desired fertility in mind, the patient opted for a conservative nonsurgical intervention. Under intravenous sedation via transvaginal ultrasound guidance, the ovarian gestational sac was aspirated with a 17-gauge in vitro fertilization needle. A total dose of 50 mg of methotrexate was instilled locally into the ectopic after which the corpus luteum cyst was disrupted. Immediate cessation of fetal heart activity was noted. A follow-up transvaginal ultrasound 1 week later confirmed adequate treatment and serum hCG levels steadily declined to an undetectable level within 8 weeks [1]. The patient subsequently conceived an intrauterine pregnancy and delivered a healthy child.

Clinical Pearls/Pitfalls

·               The original four Spiegelberg clinical criteria for the diagnosis of OEP are outdated because they require surgical intervention for evaluation and historical guidelines and treatment regimens should be reconsidered.

·               Advances in transvaginal sonography may permit earlier diagnosis of ovarian ectopic pregnancies.

·               When ectopic pregnancy is suspected, a thorough sonographic evaluation for nontubal ectopics, including ovarian, interstitial, cesarean section (C-section), and cervical sites is indicated.

·               Ovarian ectopic pregnancies are commonly mistaken for corpus luteum cyst.

·               Nonsurgical treatments of ovarian ectopic in a hemodynamically stable patients are a safe and effective minimally invasive option to be considered

Reference

1.

Pagidas K, Frishman GN. Nonsurgical management of primary ovarian pregnancy with transvaginal ultrasound-guided local administration of methotrexate. J Minim Invasive Gynecol. 2013;20(2):252–4.CrossRefPubMed

2.

Cepni I, Guralp O, Ocal P, Salahov R, Gurleyen H, Idil M. An alternative treatment option in tubal ectopic pregnancies with fetal heartbeat: aspiration of the embryo followed by single-dose methotrexate administration. Fertil Steril. 2011;96(1):79–83.CrossRefPubMed

3.

Xie PZ, Feng YZ, Zhao BH. Primary ovarian pregnancy. Report of fifteen cases. Chin Med J (Engl). 1991;104(3):217–20.

4.

Marcus SF, Brinsden PR. Primary ovarian pregnancy after in vitro fertilization and embryo transfer: report of seven cases. Fertil Steril. 1993;60(1):167–9.PubMed

5.

Joseph RJ, Irvine LM. Ovarian ectopic pregnancy: aetiology, diagnosis, and challenges in surgical management. J Obstet Gynaecol. 2012;32(5):472–4.CrossRefPubMed

6.

Hallatt JG. Primary ovarian pregnancy: a report of twenty-five cases. Am J Obstet Gynecol. 1982;143(1):55–60.PubMed

7.

Comstock C, Huston K, Lee W. The ultrasonographic appearance of ovarian ectopic pregnancies. Obstet Gynecol. 2005;105(1):42–5.CrossRefPubMed

8.

Odejinmi F, Rizzuto MI, Macrae R, Olowu O, Hussain M. Diagnosis and laparoscopic management of 12 consecutive cases of ovarian pregnancy and review of literature. J Minim Invasive Gynecol. 2009;16(3):354–9.CrossRefPubMed

9.

Kraemer B, Kraemer E, Guengoer E, Juhasz-Boess I, Solomayer EF, Wallwiener D, et al. Ovarian ectopic pregnancy: diagnosis, treatment, correlation to Carnegie stage 16 and review based on a clinical case. Fertil Steril. 2009;92(1):392–5.CrossRefPubMed

10.

Kudo M, Tanaka T, Fujimoto S. A successful treatment of left ovarian pregnancy with methotrexate. Nihon Sanka Fujinka Gakkai Zasshi. 1988;40(6):811–3.PubMed

11.

Su WH, Cheung SM, Chang SP, Chang WH, Cheng MH. Is ovarian pregnancy a medical illness? Methotrexate treatment failure and rescue by laparoscopic removal. Taiwan J Obstet Gynecol. 2008;47(4):471–3.CrossRefPubMed

12.

Raughley MJ, Frishman GN. Local treatment of ectopic pregnancy. Semin Reprod Med. 2007;25(2):99–115.CrossRefPubMed