SRU TOSHIBA RESIDENT TEACHING CASE
Live Monochorionic Adnexal Twin Ectopic Pregnancy Dejan Samardzic, MD, Claudia J. Kasales, MD, and Sabrina V. Patrone, MD CLINICAL HISTORY A pregnant 30-year-old woman presented with abdominal pain and nausea ongoing for 3 weeks. Her medical history was significant for smoking, an elective abortion in 2004, and biopsy-confirmed endometriosis in 2009. Pertinent surgical history included a left salpingo-oophorectomy due to complicated ovarian dermoid in 2002. She had regular menstrual cycles and no history of abnormal Papanicolaou smear or sexually transmitted disease. The reported first day of her last menstrual period was 3 weeks prior to presentation. She was not on contraceptives. On arrival, she was in mild abdominal discomfort with normal vital signs. Her clinical examination was normal. Quantitative human chorionic gonadotropin (hCG) measured 19,236 IU/L, and a pelvic ultrasound was performed (Figs.AYF). The patient was subsequently treated via uncomplicated laparoscopic removal of the right fallopian tube and associated adnexal mass. A twin ectopic gestation was confirmed within the fimbriated end of the fallopian tube on pathology.
DISCUSSION Ectopic pregnancy (EP) refers to implantation of the ovum in any site other than the normal decidualized endometrium and is an important cause of pregnancy-related mortality. Most recent estimates place the overall incidence at 6.4 cases for every 1000 pregnancies, a decrease from a 1992 estimate of 19.7 per 1000.1,2 This downward trend may reflect the decreased incidence of pelvic inflammatory disease, a common predisposing factor for EP.2 Other risk factors for EP include prior EP, peritubal adhesions due to previous surgery or endometriosis, tubal sterilization procedures, and smoking.3 In vitro fertilization results in 2.2 cases of EP of every 100 successful procedures, regardless of the type of assisted reproductive technology used.4 As a general rule, anything that impedes the progression of the ovum through the fallopian tube raises the risk of EP. Our patient had several risk factors including a history of prior pelvic surgery, pelvic adhesions, endometriosis, and smoking. The risk factors for EP are the same in singleton and multiple gestations.5
Received for publication April 23, 2014; accepted May 2, 2014. Department of Radiology, Penn State Milton S. Hershey Medical Center, Hershey, PA. Reprints: Dejan Samardzic, MD, Department of Radiology, Penn State Milton S. Hershey Medical Center, 500 University Dr, Hershey, PA 17033 (e-mail: [email protected]). Copyright * 2014 by Lippincott Williams & Wilkins
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Ectopic pregnancies typically present symptomatically during the sixth week of gestation.6 While the last menstrual period in our patient was reported to be 3 weeks prior to presentation, crown-rump length suggested a gestational age just over 6 weeks. The classic clinical triad of lower abdominal pain, vaginal bleeding, and adnexal mass is seen in only 45% of cases.7 The most common location for an EP is the fallopian tube as seen in our case. Ectopic pregnancies within other portions of the fallopian tube, cervix, abdomen, or the ovary itself are less common.3,6 Heterotopic pregnancies, in which an intrauterine pregnancy is coupled with an extrauterine gestation, are the most common type of twin EP.7 These occur with an incidence of 1 in 7000 pregnancies. Unilateral twin EP, on the other hand, is exceedingly rare with approximately 100 cases described in the literature.5 Most reported cases of twin EP are dichorionic or monochorionic diamniotic.5,7 Less than 10 unilateral live twin ectopic pregnancies, including both monochorionic and dichorionic cases, have been reported in the literature prior to our case.5,8 While the distinction between dichorionic and monochorionic twins is typically straightforward in the first trimester, differentiating monochorionic monoamniotic twins from monochorionic diamniotic twins can be challenging. The intervening membrane can often be difficult to confirm at ultrasound. Similarly, the number of yolk sacs is not predictive of amnionicity in early first-trimester monochorionic multiple gestations.9 Definitive amnionicity is confirmed via pathology. While not histologically confirmed in our case, nonvisualization of an intertwin membrane and the presence of a solitary yolk sac were highly suggestive of monoamniotic twinning.10 Transvaginal sonography is used to verify the presence of an intrauterine gestation, document the presence of an EP, characterize adnexal masses in pregnant (and nonpregnant) women, and follow medically treated ectopic gestations. Screening sonography has a sensitivity of 99% and specificity of 84% for the detection of EP on initial scan in pregnant patients.11 When no intrauterine gestation is seen, and there is no clear evidence of EP in a patient with elevated hCG, the pregnancy should be managed as high risk. It is important to keep in mind that a normal intrauterine twin pregnancy can be associated with higher hCG levels than singletons for any gestational age. Therefore, early intrauterine twin pregnancies can be associated with nonvisualization of an intrauterine gestation when the hCG levels are well above reported discriminatory zones. Sonographic findings should always be considered in the context of clinical and biochemical findings to avoid an incorrect diagnosis of EP when early intrauterine gestation is present but not yet visible.12 Treatment of EP is either medical (methotrexate) or surgical (laparoscopy or laparotomy). Given the efficacy and relative safety of intramuscular methotrexate administration, recent Ultrasound Quarterly
& Volume 30, Number 3, September 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Ultrasound Quarterly
& Volume 30, Number 3, September 2014
Monochorionic Adnexal Twin Ectopic Pregnancy
FIGURE. A, Sagittal transvaginal ultrasound of the uterus reveals no intrauterine gestation in the setting of a quantitative hCG of more than 19,000. B, Sagittal view of the right ovary (arrow) with color Doppler shows a corpus luteum within the right ovary. A single echogenic ring (arrowhead) adjacent to the right ovary is consistent with EP. C, Two embryos (arrows) are noted in a gestational sac within the right adnexa contained by a single echogenic ring (chorion). No intervening membrane is evident. Crown-rump length was consistent with a gestational age of just over 6 weeks. D, Only 1 yolk sac (arrow) is seen within the ectopic gestational sac. E, M-mode tracing demonstrates a heart rate of 78 beats/min for 1 of the twins. F, M-mode tracing reveals a heart rate of 113 beats/min for the second twin.
years have a seen a shift in the treatment of EP from inpatient surgical therapy to outpatient medical management. The primary goal in the treatment is preservation of fertility. Surgical intervention is required if the patient is hemodynamically unstable or has a live ectopic gestation as in our case. All cases of unilateral twin ectopics in the literature have been treated surgically.7 The combination of efficient therapeutic options, the advent of early sonographic detection, and highly sensitive hCG measurements has led to a significant decline in maternal mortality since the 1980s.13 In conclusion, we present a case of a live adnexal twin EP presumed to be monoamniotic based on imaging findings. Transvaginal sonography plays a central role in the diagnosis, management, and posttreatment follow-up of this and other forms of EP. * 2014 Lippincott Williams & Wilkins
REFERENCES 1. Hoover KW, Tao G, Kent CK. Trends in the diagnosis and treatment of ectopic pregnancy in the United States. Obstet Gynecol. 2010;115:495Y502. 2. Ectopic pregnancyVUnited States, 1990Y1992. MMWR Morb Mortal Wkly Rep. 1995;44:46Y48. 3. American College of Obstetricians and Gynecologists. Medical management of ectopic pregnancy. ACOG practice bulletin no. 94. Obstet Gynecol. 2008;111:1479Y1485. 4. Patil M. Ectopic pregnancy after infertility treatment. J Hum Reprod Sci. 2012;5(2):154Y165. 5. Ghike S, Somalwar S, Mitra K, et al. Unilateral twin ectopic pregnancy (diamniotic-dichorionic): a rare case. J S Asian Fed Obstet Gynecol. 2011;3(2):103Y105. 6. Saxon D, Falcone T, Mascha EJ, et al. A study of ruptured tubal ectopic pregnancy. Obstet Gynecol. 1997;90(1):46Y49. 7. Hois EL, Hibbeln JF, Sclamberg JS. Spontaneous twin tubal ectopic gestation. J Clin Ultrasound. 2006;34:352Y355. www.ultrasound-quarterly.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
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8. Revicky V, Krishna A, Al-Taher H. Spontaneous monochorionic monoamniotic twin tubal ectopic pregnancy. J Obstet Gynaecol. 2009;29(5):447Y448. 9. Shen O, Samueloff A, Beller U, et al. Number of yolk sacs does not predict amnionicity in early first-trimester monochorionic multiple gestations. Ultrasound Obstet Gynecol. 2006;27:53Y55. 10. Sebire NJ, Souka A, Skentou H, et al. First trimester diagnosis of monoamniotic twin pregnancies. Ultrasound Obstet Gynecol. 2000;16:223Y225.
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& Volume 30, Number 3, September 2014
11. Braffman BH, Coleman BG, Ramchandani P, et al. Emergency department screening for ectopic pregnancy: a prospective US study. Radiology. 1994;190:797Y802. 12. Doubilet PM, Benson CB, Bourne T, et al. Diagnostic criteria for nonviable pregnancy early in the first trimester. N Engl J Med. 2013;369(15):1443Y1451. 13. Creanga AA, Shapiro-Mendoza CK, Bish CL, et al. Trends in ectopic pregnancy mortality in the United States: 1980-2007. Obstet Gynecol. 2011;117(4):837Y843.
* 2014 Lippincott Williams & Wilkins
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Live Monochorionic Adnexal Twin Ectopic Pregnancy Dejan Samardzic, MD, Claudia J. Kasales, MD, and Sabrina V. Patrone, MD CLINICAL HISTORY A pregnant 30-year-old woman presented with abdominal pain and nausea ongoing for 3 weeks. Her medical history was significant for smoking, an elective abortion in 2004, and biopsy-confirmed endometriosis in 2009. Pertinent surgical history included a left salpingo-oophorectomy due to complicated ovarian dermoid in 2002. She had regular menstrual cycles and no history of abnormal Papanicolaou smear or sexually transmitted disease. The reported first day of her last menstrual period was 3 weeks prior to presentation. She was not on contraceptives. On arrival, she was in mild abdominal discomfort with normal vital signs. Her clinical examination was normal. Quantitative human chorionic gonadotropin (hCG) measured 19,236 IU/L, and a pelvic ultrasound was performed (Figs.AYF). The patient was subsequently treated via uncomplicated laparoscopic removal of the right fallopian tube and associated adnexal mass. A twin ectopic gestation was confirmed within the fimbriated end of the fallopian tube on pathology.
DISCUSSION Ectopic pregnancy (EP) refers to implantation of the ovum in any site other than the normal decidualized endometrium and is an important cause of pregnancy-related mortality. Most recent estimates place the overall incidence at 6.4 cases for every 1000 pregnancies, a decrease from a 1992 estimate of 19.7 per 1000.1,2 This downward trend may reflect the decreased incidence of pelvic inflammatory disease, a common predisposing factor for EP.2 Other risk factors for EP include prior EP, peritubal adhesions due to previous surgery or endometriosis, tubal sterilization procedures, and smoking.3 In vitro fertilization results in 2.2 cases of EP of every 100 successful procedures, regardless of the type of assisted reproductive technology used.4 As a general rule, anything that impedes the progression of the ovum through the fallopian tube raises the risk of EP. Our patient had several risk factors including a history of prior pelvic surgery, pelvic adhesions, endometriosis, and smoking. The risk factors for EP are the same in singleton and multiple gestations.5
Received for publication April 23, 2014; accepted May 2, 2014. Department of Radiology, Penn State Milton S. Hershey Medical Center, Hershey, PA. Reprints: Dejan Samardzic, MD, Department of Radiology, Penn State Milton S. Hershey Medical Center, 500 University Dr, Hershey, PA 17033 (e-mail: [email protected]). Copyright * 2014 by Lippincott Williams & Wilkins
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www.ultrasound-quarterly.com
Ectopic pregnancies typically present symptomatically during the sixth week of gestation.6 While the last menstrual period in our patient was reported to be 3 weeks prior to presentation, crown-rump length suggested a gestational age just over 6 weeks. The classic clinical triad of lower abdominal pain, vaginal bleeding, and adnexal mass is seen in only 45% of cases.7 The most common location for an EP is the fallopian tube as seen in our case. Ectopic pregnancies within other portions of the fallopian tube, cervix, abdomen, or the ovary itself are less common.3,6 Heterotopic pregnancies, in which an intrauterine pregnancy is coupled with an extrauterine gestation, are the most common type of twin EP.7 These occur with an incidence of 1 in 7000 pregnancies. Unilateral twin EP, on the other hand, is exceedingly rare with approximately 100 cases described in the literature.5 Most reported cases of twin EP are dichorionic or monochorionic diamniotic.5,7 Less than 10 unilateral live twin ectopic pregnancies, including both monochorionic and dichorionic cases, have been reported in the literature prior to our case.5,8 While the distinction between dichorionic and monochorionic twins is typically straightforward in the first trimester, differentiating monochorionic monoamniotic twins from monochorionic diamniotic twins can be challenging. The intervening membrane can often be difficult to confirm at ultrasound. Similarly, the number of yolk sacs is not predictive of amnionicity in early first-trimester monochorionic multiple gestations.9 Definitive amnionicity is confirmed via pathology. While not histologically confirmed in our case, nonvisualization of an intertwin membrane and the presence of a solitary yolk sac were highly suggestive of monoamniotic twinning.10 Transvaginal sonography is used to verify the presence of an intrauterine gestation, document the presence of an EP, characterize adnexal masses in pregnant (and nonpregnant) women, and follow medically treated ectopic gestations. Screening sonography has a sensitivity of 99% and specificity of 84% for the detection of EP on initial scan in pregnant patients.11 When no intrauterine gestation is seen, and there is no clear evidence of EP in a patient with elevated hCG, the pregnancy should be managed as high risk. It is important to keep in mind that a normal intrauterine twin pregnancy can be associated with higher hCG levels than singletons for any gestational age. Therefore, early intrauterine twin pregnancies can be associated with nonvisualization of an intrauterine gestation when the hCG levels are well above reported discriminatory zones. Sonographic findings should always be considered in the context of clinical and biochemical findings to avoid an incorrect diagnosis of EP when early intrauterine gestation is present but not yet visible.12 Treatment of EP is either medical (methotrexate) or surgical (laparoscopy or laparotomy). Given the efficacy and relative safety of intramuscular methotrexate administration, recent Ultrasound Quarterly
& Volume 30, Number 3, September 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Ultrasound Quarterly
& Volume 30, Number 3, September 2014
Monochorionic Adnexal Twin Ectopic Pregnancy
FIGURE. A, Sagittal transvaginal ultrasound of the uterus reveals no intrauterine gestation in the setting of a quantitative hCG of more than 19,000. B, Sagittal view of the right ovary (arrow) with color Doppler shows a corpus luteum within the right ovary. A single echogenic ring (arrowhead) adjacent to the right ovary is consistent with EP. C, Two embryos (arrows) are noted in a gestational sac within the right adnexa contained by a single echogenic ring (chorion). No intervening membrane is evident. Crown-rump length was consistent with a gestational age of just over 6 weeks. D, Only 1 yolk sac (arrow) is seen within the ectopic gestational sac. E, M-mode tracing demonstrates a heart rate of 78 beats/min for 1 of the twins. F, M-mode tracing reveals a heart rate of 113 beats/min for the second twin.
years have a seen a shift in the treatment of EP from inpatient surgical therapy to outpatient medical management. The primary goal in the treatment is preservation of fertility. Surgical intervention is required if the patient is hemodynamically unstable or has a live ectopic gestation as in our case. All cases of unilateral twin ectopics in the literature have been treated surgically.7 The combination of efficient therapeutic options, the advent of early sonographic detection, and highly sensitive hCG measurements has led to a significant decline in maternal mortality since the 1980s.13 In conclusion, we present a case of a live adnexal twin EP presumed to be monoamniotic based on imaging findings. Transvaginal sonography plays a central role in the diagnosis, management, and posttreatment follow-up of this and other forms of EP. * 2014 Lippincott Williams & Wilkins
REFERENCES 1. Hoover KW, Tao G, Kent CK. Trends in the diagnosis and treatment of ectopic pregnancy in the United States. Obstet Gynecol. 2010;115:495Y502. 2. Ectopic pregnancyVUnited States, 1990Y1992. MMWR Morb Mortal Wkly Rep. 1995;44:46Y48. 3. American College of Obstetricians and Gynecologists. Medical management of ectopic pregnancy. ACOG practice bulletin no. 94. Obstet Gynecol. 2008;111:1479Y1485. 4. Patil M. Ectopic pregnancy after infertility treatment. J Hum Reprod Sci. 2012;5(2):154Y165. 5. Ghike S, Somalwar S, Mitra K, et al. Unilateral twin ectopic pregnancy (diamniotic-dichorionic): a rare case. J S Asian Fed Obstet Gynecol. 2011;3(2):103Y105. 6. Saxon D, Falcone T, Mascha EJ, et al. A study of ruptured tubal ectopic pregnancy. Obstet Gynecol. 1997;90(1):46Y49. 7. Hois EL, Hibbeln JF, Sclamberg JS. Spontaneous twin tubal ectopic gestation. J Clin Ultrasound. 2006;34:352Y355. www.ultrasound-quarterly.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
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8. Revicky V, Krishna A, Al-Taher H. Spontaneous monochorionic monoamniotic twin tubal ectopic pregnancy. J Obstet Gynaecol. 2009;29(5):447Y448. 9. Shen O, Samueloff A, Beller U, et al. Number of yolk sacs does not predict amnionicity in early first-trimester monochorionic multiple gestations. Ultrasound Obstet Gynecol. 2006;27:53Y55. 10. Sebire NJ, Souka A, Skentou H, et al. First trimester diagnosis of monoamniotic twin pregnancies. Ultrasound Obstet Gynecol. 2000;16:223Y225.
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& Volume 30, Number 3, September 2014
11. Braffman BH, Coleman BG, Ramchandani P, et al. Emergency department screening for ectopic pregnancy: a prospective US study. Radiology. 1994;190:797Y802. 12. Doubilet PM, Benson CB, Bourne T, et al. Diagnostic criteria for nonviable pregnancy early in the first trimester. N Engl J Med. 2013;369(15):1443Y1451. 13. Creanga AA, Shapiro-Mendoza CK, Bish CL, et al. Trends in ectopic pregnancy mortality in the United States: 1980-2007. Obstet Gynecol. 2011;117(4):837Y843.
* 2014 Lippincott Williams & Wilkins
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
