CASE REPORT Rudimentary uterine horn pregnancy: a mystery diagnosis Tongucx Arslan, M.D., Erg€ un Bilgicx, M.D., M. Baki xSent€ urk, M.D., and Nesxe Y€ ucel, M.D. Department of Obstetrics and Gynecology, G€oztepe Training and Research Hospital, Istanbul, Turkey
Objective: To emphasize the importance of complete ultrasonographic evaluation during the first trimester of pregnancy. Design: Case report. Setting: Obstetric unit in a training and research hospital. Patient(s): A 27-year-old primigravida woman who reached 37 weeks’ gestation with a noncommunicating rudimentary horn pregnancy. Intervention(s): The accurate diagnosis of a noncommunicating rudimentary horn pregnancy was made after cesarean section at 37 weeks’ gestation. Rudimentary horn excision and ipsilateral salpingectomy were performed during exploration. Main Outcome Measure(s): Early diagnosis using sonography to prevent maternal morbidity and mortality. Result(s): A female baby with a 7/10 apgar score was delivered successfully. The patient and her baby were both discharged in good health. Conclusion(s): Rudimentary uterine horn pregnancy should always be considered as a differential diagnosis of intrauterine pregnancy in a bicornuate uterus. A thorough ultrasonographic examination should be performed on the aspects of the pregnancy and the pelvic anatomy. Lack of knowledge of and experience with m€ ullerian anomalies still makes these anomalies difficult to recognize even with laparoscopy. (Fertil Steril 2009;92:2037.e1–e3. 2009 by American Society for Reproductive Medicine.) Key Words: Unicornuate uterus, noncommunicating rudimentary horn, term pregnancy, laparoscopy
A unicornuate uterus results from the normal differentiation of only one m€ ullerian duct. Partial development of the other duct results in a rudimentary horn that is either with cavity, communicating with the uterus (type A1a) or with cavity, not communicating (type A1b), or is without a cavity (type A2) (1). Unicornuate uterus is thought to occur once per 4,020 in the general population (2), and 84% have a contralateral rudimentary horn (3). Pregnancy within a noncommunicating rudimentary horn is a rare form of ectopic gestation, reported in 1 in 76,000 pregnancies (4). The phenomenon of transperitoneal migration of either sperm or the fertilized ovum from the patent contralateral fallopian tube elucidates the cases in the literature regarding pregnancies in A1b uterine horns (5, 6). In most cases, the pregnancy continues longer than a tubal pregnancy because of the variable musculature of the horn, with a uterine horn rupture risk (4) of 50%,
Received February 11, 2009; revised July 19, 2009; accepted August 7, 2009; published online October 1, 2009. T.A. has nothing to disclose. E.B. has nothing to disclose. M.B.Sx. has nothing to disclose. N.Y. has nothing to disclose. lu Cad., Alageyik Sok., KaReprint requests: Tonguc x Arslan, M.D., Ayanog € y, Istanbul (FAX: þ90 216 369 zım Bey Apt., No:3, A/7, Feneryolu, Kadıko 75 76; E-mail:
[email protected]).
0015-0282/09/$36.00 doi:10.1016/j.fertnstert.2009.08.027
especially during the second trimester, and a neonatal survival rate (4) of 0–13%. Early diagnosis before rupture is essential for successful management to prevent maternal morbidity and mortality. Although neonatal survival has improved greatly, and maternal mortality has decreased significantly (4), only 14% of cases can be diagnosed before clinical symptoms occur (7). Early sonographic diagnosis of rudimentary uterine horn pregnancy remains elusive. Tubal, cornual, abdominal, and intrauterine pregnancy in a bicornuate uterus are common sonographic misdiagnoses. We present a case of noncommunicating rudimentary horn pregnancy that was misdiagnosed as a pregnancy in a bicornuate uterus during laparoscopy. Laparoscopy was performed in the first trimester on suggestion of a tubal ectopic pregnancy. The correct diagnosis was made before rupture at 37 weeks’ gestation, after referral to our hospital for intrauterine growth retardation (IUGR) and anhidroamnios. CASE REPORT A 27-year-old primigravida woman was referred to our obstetric unit for IUGR and anhydroamnios at 37 weeks’ gestation. In her obstetric history, it was noted that at 8 weeks’ gestation, the endometrial cavity was observed to be empty
Fertility and Sterility Vol. 92, No. 6, December 2009 Copyright ª2009 American Society for Reproductive Medicine, Published by Elsevier Inc.
2037.e1
during the first-trimester ultrasound, and the fetus was defined in the right tube. She did not have any accompanying symptoms. She underwent a laparoscopy for tubal ectopic pregnancy and was misdiagnosed as an intrauterine pregnancy in a bicornuate uterus. After that, her pregnancy proceeded normally. There was no history of abdominopelvic pain before or during the pregnancy. At 37 weeks’ gestation, the patient had IUGR and oligoanhidroamnios and was referred to our hospital in case the neonatal intensive care unit was needed. Obstetric ultrasound assesment showed 7 weeks of asymmetric growth restriction with markedly decreased amniotic fluid. On pelvic examination, there was a closed cervix, and the uterus corresponded to 30–32 weeks’ gestation. Because she had a diagnosis of bicornuate uterus, endovaginal ultrasonography was performed and showed a normal-size nonpregnant uterus, and a right-sided horn pregnancy. The cardiotocographic tracing of the fetal heart rate was normal. After the patient gave fully informed consent, surgery was performed. A laparotomy revealed a right-sided, 30-weekold, rudimentary horn that was connected to the unicornuate uterus by a 3-cm–thick fibromuscular tissue (Fig 1). The right tube and ovary were attached to the rudimentary horn. The left adnexa appeared healthy. We did not notice any endometriotic implants. A live born male child weighing 1,370 g was delivered with breech presentation. Despite the meconium-stained amniotic fluid, 1-minute apgar score was 7. We did not deliver the placenta. Instead, we excised the blind horn with ipsilateral salpingectomy (Fig 2). Postoperative follow-up was uneventful, and she was discharged 5 days after surgery. After being kept in the neonatal intensive care unit for 15 days without intubation, the baby was discharged in good condition. In addition, upon investigation the patient’s urinary tract was observed to be normal.
FIGURE 1 Rudimentary horn with the placenta, and the normalsize uterus.
Arslan. Rudimentary uterine horn pregnancy: a mystery diagnosis. Fertil Steril 2009.
2037.e2
Arslan et al.
FIGURE 2 After excision of the rudimentary horn with the ipsilateral salpinx.
Arslan. Rudimentary uterine horn pregnancy: a mystery diagnosis. Fertil Steril 2009.
DISCUSSION Pregnancy within a noncommunicating rudimentary horn is a rare form of ectopic gestation, reported in 1 in 76,000 pregnancies (4). The nature of rudimentary uterine horn pregnancy usually leads to rupture during the second or third trimester, resulting in life-threatening hemoperitoneum. Early diagnosis is the key to successful management of rudimentary uterine horn pregnancy. A thorough ultrasound examination during the first trimester is the most important part of diagnosis, because the pregnancy still lies in the pelvis. Tsafrir et al. (8) proposed the following criteria for ultrasonographic diagnosis: [1] a pseudo pattern of an asymmetrical bicornuate uterus, [2] absent visual continuity tissue surrounding the gestation sac and the uterine cervix, and [3] the presence of myometrial tissue surrounding the gestation sac. However, preoperative diagnosis remains challenging, as noted by S€onmezer et al (9). In a review (7), sensitivity of sonograpy for diagnosis was shown to be 26%. These data indicate that rudimentary uterine horn pregnancy should always be considered as a differential diagnosis of tubal pregnancy and intrauterine pregnancy in a bicornuate uterus. A tubal pregnancy will not show a ring of myometrium surrounding the gestational sac, and for a pregnancy in a bicornuate uterus, continuity between the endometrium lining the sac and the other uterine horn is typical. In case of suspicion of rudimentary uterine horn pregnancy, magnetic resonance imaging (MRI) has proven to be a useful tool, both for the diagnosis and for the choice of surgical approaches (8). An MRI examination is also helpful to determine whether any urinary tract abnormalities are present. The initial diagnosis given to our patient was tubal ectopic pregnancy. Unfortunately, she received a misdiagnosis of intrauterine pregnancy in a bicornuate uterus during
Rudimentary uterine horn pregnancy: a mystery diagnosis
Vol. 92, No. 6, December 2009
laparoscopic exploration. Occasional cases (gynecologic and obstetric) involving confusion in diagnosis that required further evaluation have been reported in the literature (10, 11); this is because uterine anomalies are uncommon and usually low on the list of differential diagnoses. This case could be identified via neither ultrasonography nor laparoscopy. The confusion at the time of laparoscopy in this case is an extreme aberration, but reveals the inadequacy in identifying m€ ullerian anomalies. We were able to diagnose this case accurately via a carefully performed ultrasound examination. Only 30% of rudimentary uterine horn gestations progess to term (4), and there is a low newborn survival rate (4), ranging 0–13%. In our case, because of the delay in diagnosis, the pregnancy reached 37 weeks’ gestation with severe fetal growth restriction and anhidroamnios, as expected. These complications could be explained by incompatibility of the wall structure and disturbance of the blood flow (2). When ectopic pregnancy within a rudimentary uterine horn occurs, whether combined with medical treatment according to the gestation week, surgical removal of the horn along with ipsilateral tuba is a requisite because of the high risk of rupture (2, 5, 7, 11). We performed a successful excision of the noncommunicating right rudimentary horn with ipsilateral salpingectomy after the delivery of the baby. CONCLUSION Rudimentary uterine horn pregnancy should always be considered as a differential diagnosis of intrauterine pregnancy in a bicornuate uterus. A thorough ultrasound examination should be performed on the aspects of the pregnancy
Fertility and Sterility
and on the pelvic anatomy. Lack of knowledge of and experience with m€ullerian anomalies still makes them difficult to recognize even with laparoscopy, as seen in this case.
REFERENCES 1. The American Fertility Society classifications of adnexal adhesions, distal tubal occlusion, tubal occlusion secondary to tubal ligation, tubal pregnancies, m€ullerian anomalies and intrauterine adhesions. Fertil Steril 1988;49:944–55. 2. Reichman D, Laufer MR, Robinson BK. Pregnancy outcomes in unicornuate uteri: a review. Fertil Steril 2008;91:1886–94. 3. Heinonen P. Unicornuate uterus and rudimentary horn. Fertil Steril 1997;68:224–30. 4. Nahum GG. Rudimentary uterine horn pregnancy. The 20th-century worldwide experience of 588 cases. J Reprod Med 2002;47:151–63. 5. Nahum G, Stanislaw H, McMahon C. Preventing ectopic pregnancies: how often does transperitoneal transmigration of sperm occur in effecting human pregnancy? BJOG 2004;111:706–14. 6. O’Leary JL, O’Leary JA. Rudimentary horn pregnancy. Obstet Gynecol 1963;22:371–5. 7. Jayasinghe Y, Rane A, Stalewski H, Grover S. The presentation and early diagnosis of the rudimentary uterine horn. Obstet Gynecol 2005;105: 1456–67. 8. Tsafrir A, Rojansky N, Sela HY, Gomori JM, Nadjari M. Rudimentary horn pregnancy: first trimester prerupture sonographic diagnosis and confirmation by magnetic resonance imaging. J Ultrasound Med 2005;24:219–23. 9. S€onmezer M, Taskin S. Atabekoglu C, G€ung€or M, Unl€u C. Laparoscopic management of rudimentary uterine horn pregnancy: case report and literature review. JSLS 2006;10:396–9. 10. Stitely ML, Hopkins K. Laparoscopic removal of a rudimentary uterine horn in a previously hysterectomized patient. JSLS 2006;10(2):257–8. Apr-Jun. 11. Park JK, Dominguez CE. Combined medical and surgical management of rudimentary uterine horn pregnancy. JSLS 2007;11:119–22.
2037.e3
