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Case Report  |   September 2018
Novel Management of Ectopic Pregnancy in a Noncommunicating Rudimentary Horn of a Unicornuate Uterus
Author Notes
  • From Vitality Gynecology, Aesthetics & Wellness in Lemoyne, Pennsylvania (Dr Herchelroath); the Johns Hopkins Center for Fetal Therapy in Baltimore, Maryland (Dr Miller); and the Departments of Gynecology & Obstetrics and Surgery at Johns Hopkins Hospital in Baltimore, Maryland (Dr Wang). 
  • Financial Disclosures: None reported. 
  • Support: None reported. 
  •  *Address correspondence to Deborah Herchelroath, DO, Vitality Gynecology, Aesthetics & Wellness, 1035 Mumma Rd, Ste 301, Lemoyne, PA 17043-1147. Email: drh@vitalitygyn.com
     
Article Information
Obstetrics and Gynecology / Pediatrics
Case Report   |   September 2018
Novel Management of Ectopic Pregnancy in a Noncommunicating Rudimentary Horn of a Unicornuate Uterus
The Journal of the American Osteopathic Association, September 2018, Vol. 118, 623-626. doi:https://doi.org/10.7556/jaoa.2018.137
The Journal of the American Osteopathic Association, September 2018, Vol. 118, 623-626. doi:https://doi.org/10.7556/jaoa.2018.137
Abstract

Pregnancy in a rudimentary horn is a rarely encountered form of ectopic pregnancy and is often an emergent situation because of the risk of rupture of the horn. A 31-year-old gravida 3 para 1 woman with 7 to 8 weeks’ gestational age was found to have a viable pregnancy in a rudimentary noncommunicating horn of a unicornuate uterus. She elected termination of the pregnancy via local intracardiac lidocaine and intra-amniotic methotrexate injections. Subsequent removal of the rudimentary horn was necessary to prevent recurrence. Because of the risk of rupture, the diagnosis and management of an ectopic pregnancy in a rudimentary horn can be emergent.

A unicornuate uterus with a rudimentary horn occurs infrequently (approximately 1:100,000 females) and is the result of an asymmetric lateral fusion defect of the Müllerian ducts.1 While most rudimentary horns are asymptomatic, noncommunicating horns may contain functional endometrial cells that shed monthly, resulting in cyclic dysmenorrhea or endometriosis.1,2 In rare instances, pregnancy can occur in the rudimentary horn; an incidence of approximately 1:76,000 pregnancies has been reported.2-4 It is suspected that pregnancy occurs in a noncommunicating horn via transperitoneal migration of sperm or a fertilized ovum from the contralateral side or through a microscopic fistulous tract with the unicornuate uterus.2,4,5 The greatest concern when managing a pregnancy in a rudimentary horn is the risk of uterine rupture. 
Most rudimentary horn pregnancies have poor outcomes due to catastrophic bleeding secondary to uterine rupture. The high rate of associated complications occurs for several reasons. First, a rudimentary horn is often asymptomatic unless incidentally discovered during the evaluation of pelvic pain, workup for infertility, or workup for pregnancy loss. Second, these pregnancies are most often discovered in the second trimester, when uterine rupture is most likely to occur.3,4,6 Finally, ultrasonographic identification of a rudimentary horn pregnancy is technically challenging and the diagnostic accuracy is limited, with a sensitivity of 26% to 30%.2,4 Although the criterion standard for evaluation of Müllerian anomalies is magnetic resonance imaging, this test is costly and infrequently performed for this indication. 
We present a case in which the diagnosis was made in the first trimester, medical termination was elected, and subsequent removal of the horn was performed to prevent recurrence and to allow for future conception. 
Report of Case
A 31-year-old gravida 3 para 1 woman with a history of a left unicornuate uterus with a noncommunicating rudimentary right horn came to our facility to establish care. At another facility approximately 2 to 3 weeks earlier, vaginal ultrasonography showed a 5-week intrauterine pregnancy in the left unicornuate uterus with a fetal pole. Findings on vaginal ultrasonography at the current visit were suspicious for an 8-week pregnancy in the right noncommunicating horn. This finding was confirmed by a maternal fetal medicine specialist. The patient was counseled regarding treatment options and the significantly higher risk of rupture of the rudimentary horn as the gestational age progressed. She was referred to Johns Hopkins Hospital for evaluation and management. 
Within a week, ultrasonography performed at the Johns Hopkins Hospital Center for Fetal Therapy confirmed a viable pregnancy of 7 weeks, 4 days, consistent with gestational dating, in the noncommunicating rudimentary horn on the right (Figure 1). The findings and management options were discussed with the patient and her family, and she elected to terminate the pregnancy via intracardiac lidocaine injection and intra-amniotic methotrexate injection. 
Figure 1.
Ultrasonographic image of a right cornual ectopic pregnancy (red arrow) with the unicornuate uterus visible (thickened endometrium between white arrows) in a 31-year-old woman.
Figure 1.
Ultrasonographic image of a right cornual ectopic pregnancy (red arrow) with the unicornuate uterus visible (thickened endometrium between white arrows) in a 31-year-old woman.
Eighteen days later, the procedure was performed transabdominally using ultrasonographic guidance. One percent lidocaine (1 mL) was injected directly into the fetal pole, resulting in fetal bradycardia. Extraembryonic fluid was drained, and 101.5 mg of methotrexate in a total of 4.06 mL was injected into the gestational sac. 
The patient's initial quantitative β human chorionic gonadotropin (β-hCG) level was 123,523. Day 4 β-hCG level was 157,824, and day 7 level was 119,472. Weekly β-hCG levels were then tested. Week 1 was 18,648, week 2 was 2173, and week 3 was 915. Five days after the injection, ultrasonographic imaging verified fetal death. 
The patient desired definitive therapy in the form of resection of the rudimentary horn to prevent recurrence in future conception. The operation was performed approximately 1 month from the date of lidocaine and methotrexate injection and termination of the pregnancy. A laparoscopic resection of the right rudimentary uterine horn, right salpingectomy, and lysis of adhesions was performed without incident (Figure 2 and Figure 3). The patient was discharged home on postoperative day 1 and had an uncomplicated postoperative course. 
Figure 2.
Laparoscopic view of the right rudimentary horn (red arrow) in a 31-year-old woman with ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus. The white arrow points to a thick band connecting the unicornuate uterus in the midline to the rudimentary horn.
Figure 2.
Laparoscopic view of the right rudimentary horn (red arrow) in a 31-year-old woman with ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus. The white arrow points to a thick band connecting the unicornuate uterus in the midline to the rudimentary horn.
Figure 3.
Cross-section of the right rudimentary horn after laparoscopic removal from a 31-year-old woman. The patient had undergone medical termination of an ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus 1 month earlier.
Figure 3.
Cross-section of the right rudimentary horn after laparoscopic removal from a 31-year-old woman. The patient had undergone medical termination of an ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus 1 month earlier.
Discussion
To our knowledge, ours is the only case that has been reported in which local lidocaine and methotrexate were used as the primary method of terminating an ectopic pregnancy in the rudimentary horn. We believed that systemic methotrexate as the primary method would have a higher risk of failure due to several contraindications, including the high β-hCG level and positive fetal cardiac activity. We also extrapolated that this ectopic pregnancy could behave like a cesarean scar ectopic pregnancy, for which perfusion could be suboptimal. Therefore, we used lidocaine as an adjunct to induce fetal death to ensure that the β-hCG level would decrease, thereby decreasing vascularity. 
Although the fallopian tubes are the most common location for an ectopic pregnancy, other ectopic locations include the ovary, omentum, and abdomen. There is often confusion regarding the nomenclature of cornual and interstitial pregnancies. According to Williams Obstetrics,7 a cornual pregnancy is a pregnancy located in the upper and lateral uterine cavity. An interstitial pregnancy occurs within the proximal intramural portion of the fallopian tube. In the current case, the pregnancy was in an ectopic location but was considered a noncommunicating rudimentary horn pregnancy because it resided in the rudimentary horn of the anomalous unicornuate uterus and had no evidence of communication with the endometrial cavity.7 
Ectopic pregnancy in a rudimentary horn has traditionally been managed with resection of the horn with the pregnancy in situ (if diagnosed before rupture). However, the majority of unrecognized cases present with hemoperitoneum and uterine rupture before the third trimester.1,8 Live births following a pregnancy in a rudimentary horn have been reported.9,10 
An option for treating a patient who is hemodynamically stable with an ectopic pregnancy includes the use of systemic methotrexate. Cases of interstitial and tubal ectopic pregnancies terminated with local methotrexate have been reported.11,12 However, local methotrexate injection has been infrequently reported for managing rudimentary horn pregnancies, most likely because of their late presentation. Sevtap et al6 described a rudimentary horn pregnancy managed with local methotrexate. A case13 of systemic methotrexate used to manage a rudimentary horn pregnancy was reported, but at the time treatment was initiated, it was believed that the pregnancy was located in one horn of a bicornuate uterus. Once the diagnosis of rudimentary horn pregnancy was made, the rudimentary horn was removed. 
As stated by both Mavrelos et al2 and Nanda et al3, there is often a thick vascular band connecting the horn to the uterus, which, especially in the gravid state, can lead to increased bleeding when resected. To mitigate the possibility of significant blood loss at the time of surgical resection of a gravid rudimentary horn, we opted to wait 4 weeks after lidocaine and methotrexate injection to proceed with surgery. 
According to a 2017 review of ectopic pregnancies in uncommon locations by Martingano et al,14 somatic dysfunction at T10 to L2 and absent Chapman reflex points would be expected in a patient with a noncommunicating rudimentary horn pregnancy based on similar findings in cornual ectopic pregnancies.14 An osteopathic structural examination was not performed in the current case, so no comparison can be made. 
Conclusion
As imaging improves, the ability to detect Müllerian anomalies will also improve. As a result, accurate and early diagnosis will allow for medical termination of cornual ectopic pregnancies with less need for immediate surgical intervention. The outlook for decreasing morbidity and mortality that can be associated with unrecognized cornual pregnancies is good. In the meantime, our solution for primary management of this potentially lethal situation resulted in the safest approach to both honor the family's wishes and preserve the mother's good health and future fertility. 
References
Dhar H. Rupture of non-communicating rudimentary uterine horn pregnancy. J Coll Physicians Surg Pak. 2008;18(1):53-54. doi: 01.2008/JCPSP.5354 [PubMed]
Mavrelos D, Sawyer E, Helmy S, Holland TK, Ben-Nagi J, Jurkovic D. Ultrasound diagnosis of ectopic pregnancy in the non-communicating horn of a unicornuate uterus (cornual pregnancy). Ultrasound Obstet Gynecol. 2007;30(5):765-770. doi: 10.1002/uog.5131 [CrossRef] [PubMed]
Nanda S, Dahiya K, Sharma N, Aggarwal D, Sighal SR, Sangwa N. Successful twin pregnancy in a unicornuate uterus with one fetus in the non-communicating rudimentary horn. Arch Gynecol Obstet. 2009;280(6):993-995. doi: 10.1007/s00404-009-1028-x [CrossRef] [PubMed]
Thakur S, Sood A, Sharma C. Ruptured noncommunicating rudimentary horn pregnancy at 19 weeks with previous cesarean delivery: a case report. Case Rep Obstet Gynecol. 2012;2012:308476. doi: 10.1155/2012/308476 [PubMed]
Moawad GN, Abi Khalil ED. A case of recurrent rudimentary horn ectopic pregnancies managed by methotrexate therapy and laparoscopic excision of the rudimentary horn. Case Rep Obstet Gynecol. 2016;2016:5747524. doi: 10.1155/2016/5747524 [PubMed]
Sevtap HK, Aral AM, Sertac B. An early diagnosis and successful local medical treatment of a rudimentary uterine horn pregnancy: a case report. Arch Gynecol Obstet. 2007;275:297-298. doi: 10.1007/s00404-006-0232-1 [CrossRef] [PubMed]
Cunningham G, Leveno K, Bloom S, Hauth J, Rouse D, Spong C. Williams Obstetrics. 23rd ed. New York, NY: McGraw Hill Medical; 2009:241.
Nahum GG. Rudimentary uterine horn pregnancy. the 20th-century worldwide experience of 588 cases. J Reprod Med. 2002;47(2):151-163.
Iyoke C, Okafor C, Ugwu G, Oforbuike C. Live birth following a term pregnancy in a non-communicating rudimentary horn of a unicornuate uterus. Ann Med Health Sci Res. 2014;4(1):126-128. doi: 10.4103/2141-9248.126622 [CrossRef] [PubMed]
Cheng C, Tang W, Zhang L, et al. Unruptured pregnancy in a noncommunicating rudimentary horn at 37 weeks with a live fetus: a case report. J Biomed Res. 2015;29(1):83-86. doi: 10.7555/JBR.29.20130089 [PubMed]
Hafner T, Aslam N, Ross JA, Zosmer N, Jurkovic D. The effectiveness of non-surgical management of early interstitial pregnancy: a report of ten cases and review of the literature. Ultrasound Obstet Gynecol. 1999;13(2):131-136. doi: 10.1046/j.1469-0705.1999.13020131.x [CrossRef] [PubMed]
Mesogitis SA, Daskalakis GJ, Antsaklis AJ, Papantoniou NE, Papageorgiou JS, Michalas SK. Local application of methotrexate for ectopic pregnancy with a percutaneous puncturing technique. Gynecol Obstet Invest. 1998;45(3):154-158. doi: 10.1159/000009946 [CrossRef] [PubMed]
Edelman AB, Jensen JT, Lee DM, Nichols MD. Successful medical abortion of a pregnancy within a noncommunicating rudimentary uterine horn. Am J Obstet Gynecol. 2003;189(3):886-887. [CrossRef] [PubMed]
Martingano D, Canepa H, Fararooy S, et al. Somatic dysfunction in the diagnosis of uncommon ectopic pregnancies: surgical correlation and comparison with related pathologic findings. J Am Osteopath Assoc. 2017;117(2):86-97. doi: 10.7556/jaoa.2017.019 [CrossRef] [PubMed]
Figure 1.
Ultrasonographic image of a right cornual ectopic pregnancy (red arrow) with the unicornuate uterus visible (thickened endometrium between white arrows) in a 31-year-old woman.
Figure 1.
Ultrasonographic image of a right cornual ectopic pregnancy (red arrow) with the unicornuate uterus visible (thickened endometrium between white arrows) in a 31-year-old woman.
Figure 2.
Laparoscopic view of the right rudimentary horn (red arrow) in a 31-year-old woman with ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus. The white arrow points to a thick band connecting the unicornuate uterus in the midline to the rudimentary horn.
Figure 2.
Laparoscopic view of the right rudimentary horn (red arrow) in a 31-year-old woman with ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus. The white arrow points to a thick band connecting the unicornuate uterus in the midline to the rudimentary horn.
Figure 3.
Cross-section of the right rudimentary horn after laparoscopic removal from a 31-year-old woman. The patient had undergone medical termination of an ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus 1 month earlier.
Figure 3.
Cross-section of the right rudimentary horn after laparoscopic removal from a 31-year-old woman. The patient had undergone medical termination of an ectopic pregnancy in a noncommunicating rudimentary horn of a unicornuate uterus 1 month earlier.