Novel Insights from Clinical Practice Fetal Diagn Ther 2015;37:154–156 DOI: 10.1159/000367969
Received: July 29, 2014 Accepted after revision: August 27, 2014 Published online: January 27, 2015
Monochorionic Monozygotic Twin Pregnancy Complicated with Twin-Twin Transfusion Syndrome Presenting with an Obvious Lambda Sign in the First Trimester Akiko Yamashita Keisuke Ishii Nobuhiro Hidaka Naoto Yonetani Shusaku Hayashi Makoto Takeuchi Nobuaki Mitsuda Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Osaka, Japan
Established Facts • The ultrasound markers, including the lambda sign/T sign and the number of placental masses before 14 weeks’ gestation, have high sensitivity and specificity for chorionicity determination in twin pregnancies.
Novel Insights • Although it is rare, the twin pregnancy may consist of monochorionic twins even if the lambda sign is documented.
Key Words Lambda sign · Monochorionic twin · Monozygotic twin · Short tandem repeat · Twin-twin transfusion syndrome
investigation, DNA typing confirmed that the twin set was monochorionic and monozygotic. This case illustrates that although extremely uncommon, the presence of lambda sign does not exclude monochorionic pregnancy. © 2015 S. Karger AG, Basel
© 2015 S. Karger AG, Basel 1015–3837/15/0372–0154$39.50/0 E-Mail [email protected] www.karger.com/fdt
Case Report A 39-year-old nulliparous woman successfully conceived through in vitro fertilization and cleavage-stage single embryo transfer with an intracytoplasmic sperm injection. Transvaginal
Keisuke Ishii Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, 840 Murodo Izumi, Osaka 594-1101 (Japan) E-Mail keisui @ mch.pref.osaka.jp
Downloaded by: Dahlgree Med. Library, Goergetown Univ. 141.161.91.14 - 5/23/2015 8:09:54 AM
Abstract In this report, we present a case of twin-twin transfusion syndrome in the presence of the thick dividing wall of each sac in dichorionic twins. The dichorionic diagnosis was based on the presence of the lambda sign at the first-trimester ultrasound evaluation. In addition to fetoscopic and pathological
Fig. 1. Ultrasound imaging of the lambda sign in the case. a Two gestational sacs
a
b
Fig. 2. Fetoscopic documentation of the dividing membrane at la-
ser coagulation for twin-twin transfusion syndrome. Fetoscopy demonstrated that the thick dividing membrane in a recipient’s sac was raised from a posterior single placenta.
Table 1. The result of deoxypentose nucleic acid (DNA) zygosity
study using Short Tandem Repeat (STR) STR
Twin A
D3S1358 vWA D16S539 D2S1338 D8S1179 D21S11 D18S51 D19S433 TH01 FGA D5S818 D13S317 D7S820 TPOX CSF1PO
16 14 11 19 10 31.2 15 12 8 21 11 10 12 8 11
Twin B 17 19 – 25 17 32.2 – 14 9.3 26 13 11 – – 12
16 14 11 19 10 31.2 15 12 8 21 11 10 12 8 11
LR 17 19 – 25 17 32.2 – 14 9.3 26 13 11 – – 12
2.5 3.02 2.82 3.1 3.47 3.35 2.88 2.81 3.75 3.35 2.6 2.89 2.73 2.05 2.23
STR = Short tandem repeat; LR = likelihood ratio.
Macroscopic investigation of the placenta revealed that the thick dividing membrane in proximity to the single placenta was composed of fused chorion and existed in combination with the thinner part of the membrane that was composed of only 2 amnions. All vascular anastomoses were interrupted according to the results of a dye injection test. A deoxypentose nucleic acid (DNA) zygosity study using short tandem repeat (STR) to determine zygosity of the twins demonstrated that all classes of STR examined were matched between the fetuses A and B, showing a 99.9% probability of monozygosity (table 1).
sonography at 9 weeks’ gestation demonstrated the characteristic ‘lambda sign’ feature of dichorionic diamniotic twins: 2 gestational sacs separated by a thick, curved septal wall (fig. 1a). The case was accordingly classified as dichorionic. At 17 weeks’ gestation, ultrasonography displayed polyhydramnios in twin A and anhydramnios in twin B. The patient was provisionally diagnosed with twin-twin transfusion syndrome. However, the chorionicity could not be determined, because the lambda sign suggestive of dichorionic twins between each sac remained apparently visualized (fig. 1b). After the patient gave informed consent, fetoscopic laser coagulation of chorionic vessels was successfully performed at 17 weeks’ gestation. Fetoscopy demonstrated that the thick dividing wall had partitioned off a part of twin A’s single amniotic cavity, whereas a part of the filmy, semitransparent dividing membrane was sticking to twin B. Several chorionic vascular anastomoses were identified on the surface of a flattened region of the placenta next to the thick dividing wall (fig. 2). After the surgery, each twin’s MVP had normalized. At 37 weeks, two healthy female infants were born via cesarean delivery.
This case report examined first- through second-trimester TTTS in the thick dividing wall of each sac in twins in the presence of the ‘lambda sign’ characteristic of di-
Monochorionic Monozygotic Twin Pregnancy with an Obvious Lambda Sign
Fetal Diagn Ther 2015;37:154–156 DOI: 10.1159/000367969
Discussion
155
Downloaded by: Dahlgree Med. Library, Goergetown Univ. 141.161.91.14 - 5/23/2015 8:09:54 AM
Color version available online
along with lambda sign were identified by transvaginal ultrasonography at 9 weeks’ gestational age. b An obvious lambda sign was identified, via transabdominal ultrasonography at 17 weeks’ gestation.
chorionic twins. In this case, the chorionicity and zygosity were ultimately found to be monochorionic and monozygotic after DNA typing each fetus. The lambda sign, which is the triangular tissue projection extending from the base of the intertwine membrane, has been commonly used for antenatal ultrasonographic chorionicity determination in twin pregnancies. The determination of chorionicity using the lambda sign has been regarded as the most reliable during only the first trimester, because it becomes gradually more difficult to detect as gestation time increases [1, 2]. The sensitivity and the specificity for the lambda sign in combination with other ultrasound markers, including fetal sex and number of placental masses before 14 weeks’ gestation, are approximately 89.9–100.0 and 97.4–99.8%, respectively [3–5].
However, several cases have been reported that are inconsistent with the accepted clinical usefulness of ultrasound markers for determining chorionicity. The cases of monochorionic diamniotic (MCDA) twins with separate placental masses [6] and sex-discordant monochorionic twins, indicating the dizygotic MCDA condition, were also reported [7]. These phenomena present a dilemma when determining the chorionicity of twin pregnancies. The present case is similarly problematic in terms of using the lambda sign after the first trimester. We should be aware of the potential ambiguity of ultrasonographic diagnosis of chorionicity in twin pregnancies as gestation progresses. Furthermore, in cases of twin pregnancies where a marked difference in amniotic fluid volume appears, the possibility of MCDA should be taken into account.
References
156
4 Lee YM, Cleary-Goldman J, Thaker HM, Simpson LL: Antenatal sonographic prediction of twin chorionicity. Am J Obstet Gynecol 2006;195:863–867. 5 Dias T, Arcangeli T, Bhide A, Napolitano R, Mahsud-Dornan S, Thilaganathan B: Firsttrimester ultrasound determination of chorionicity in twin pregnancy. Ultrasound Obstet Gynecol 2011;38:530–532.
Fetal Diagn Ther 2015;37:154–156 DOI: 10.1159/000367969
6 Lopriore E, Sueters M, Middeldorp JM, Klumper F, Oepkes D, Vandenbussche FP: Twin pregnancies with two separate placental masses can still be monochorionic and have vascular anastomoses. Am J Obstet Gynecol 2006;194:804–808. 7 Souter VL, Kapur RP, Nyholt DR, Skogerboe K, Myerson D, Ton CC, Opheim KE, Easterling TR, Shields LE, Montgomery GW, Glass IA: A report of dizygous monochorionic twins. N Engl J Med 2003;349:154–158.
Yamashita/Ishii/Hidaka/Yonetani/ Hayashi/Takeuchi/Mitsuda
Downloaded by: Dahlgree Med. Library, Goergetown Univ. 141.161.91.14 - 5/23/2015 8:09:54 AM
1 Bessis R, Papiernik E: Echographic imagery of amniotic membranes in twin pregnancies. Prog Clin Biol Res 1981;69A:183–187. 2 Sepulveda W: Chorionicity determination in twin pregnancies: double trouble. Ultrasound Obstet Gynecol 1997;10:79–81. 3 Menon DK: A retrospective study of the accuracy of sonographic chorionicity determination in twin pregnancies. Twin Res Hum Genet 2005;8:259–261.
Received: July 29, 2014 Accepted after revision: August 27, 2014 Published online: January 27, 2015
Monochorionic Monozygotic Twin Pregnancy Complicated with Twin-Twin Transfusion Syndrome Presenting with an Obvious Lambda Sign in the First Trimester Akiko Yamashita Keisuke Ishii Nobuhiro Hidaka Naoto Yonetani Shusaku Hayashi Makoto Takeuchi Nobuaki Mitsuda Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Osaka, Japan
Established Facts • The ultrasound markers, including the lambda sign/T sign and the number of placental masses before 14 weeks’ gestation, have high sensitivity and specificity for chorionicity determination in twin pregnancies.
Novel Insights • Although it is rare, the twin pregnancy may consist of monochorionic twins even if the lambda sign is documented.
Key Words Lambda sign · Monochorionic twin · Monozygotic twin · Short tandem repeat · Twin-twin transfusion syndrome
investigation, DNA typing confirmed that the twin set was monochorionic and monozygotic. This case illustrates that although extremely uncommon, the presence of lambda sign does not exclude monochorionic pregnancy. © 2015 S. Karger AG, Basel
© 2015 S. Karger AG, Basel 1015–3837/15/0372–0154$39.50/0 E-Mail [email protected] www.karger.com/fdt
Case Report A 39-year-old nulliparous woman successfully conceived through in vitro fertilization and cleavage-stage single embryo transfer with an intracytoplasmic sperm injection. Transvaginal
Keisuke Ishii Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, 840 Murodo Izumi, Osaka 594-1101 (Japan) E-Mail keisui @ mch.pref.osaka.jp
Downloaded by: Dahlgree Med. Library, Goergetown Univ. 141.161.91.14 - 5/23/2015 8:09:54 AM
Abstract In this report, we present a case of twin-twin transfusion syndrome in the presence of the thick dividing wall of each sac in dichorionic twins. The dichorionic diagnosis was based on the presence of the lambda sign at the first-trimester ultrasound evaluation. In addition to fetoscopic and pathological
Fig. 1. Ultrasound imaging of the lambda sign in the case. a Two gestational sacs
a
b
Fig. 2. Fetoscopic documentation of the dividing membrane at la-
ser coagulation for twin-twin transfusion syndrome. Fetoscopy demonstrated that the thick dividing membrane in a recipient’s sac was raised from a posterior single placenta.
Table 1. The result of deoxypentose nucleic acid (DNA) zygosity
study using Short Tandem Repeat (STR) STR
Twin A
D3S1358 vWA D16S539 D2S1338 D8S1179 D21S11 D18S51 D19S433 TH01 FGA D5S818 D13S317 D7S820 TPOX CSF1PO
16 14 11 19 10 31.2 15 12 8 21 11 10 12 8 11
Twin B 17 19 – 25 17 32.2 – 14 9.3 26 13 11 – – 12
16 14 11 19 10 31.2 15 12 8 21 11 10 12 8 11
LR 17 19 – 25 17 32.2 – 14 9.3 26 13 11 – – 12
2.5 3.02 2.82 3.1 3.47 3.35 2.88 2.81 3.75 3.35 2.6 2.89 2.73 2.05 2.23
STR = Short tandem repeat; LR = likelihood ratio.
Macroscopic investigation of the placenta revealed that the thick dividing membrane in proximity to the single placenta was composed of fused chorion and existed in combination with the thinner part of the membrane that was composed of only 2 amnions. All vascular anastomoses were interrupted according to the results of a dye injection test. A deoxypentose nucleic acid (DNA) zygosity study using short tandem repeat (STR) to determine zygosity of the twins demonstrated that all classes of STR examined were matched between the fetuses A and B, showing a 99.9% probability of monozygosity (table 1).
sonography at 9 weeks’ gestation demonstrated the characteristic ‘lambda sign’ feature of dichorionic diamniotic twins: 2 gestational sacs separated by a thick, curved septal wall (fig. 1a). The case was accordingly classified as dichorionic. At 17 weeks’ gestation, ultrasonography displayed polyhydramnios in twin A and anhydramnios in twin B. The patient was provisionally diagnosed with twin-twin transfusion syndrome. However, the chorionicity could not be determined, because the lambda sign suggestive of dichorionic twins between each sac remained apparently visualized (fig. 1b). After the patient gave informed consent, fetoscopic laser coagulation of chorionic vessels was successfully performed at 17 weeks’ gestation. Fetoscopy demonstrated that the thick dividing wall had partitioned off a part of twin A’s single amniotic cavity, whereas a part of the filmy, semitransparent dividing membrane was sticking to twin B. Several chorionic vascular anastomoses were identified on the surface of a flattened region of the placenta next to the thick dividing wall (fig. 2). After the surgery, each twin’s MVP had normalized. At 37 weeks, two healthy female infants were born via cesarean delivery.
This case report examined first- through second-trimester TTTS in the thick dividing wall of each sac in twins in the presence of the ‘lambda sign’ characteristic of di-
Monochorionic Monozygotic Twin Pregnancy with an Obvious Lambda Sign
Fetal Diagn Ther 2015;37:154–156 DOI: 10.1159/000367969
Discussion
155
Downloaded by: Dahlgree Med. Library, Goergetown Univ. 141.161.91.14 - 5/23/2015 8:09:54 AM
Color version available online
along with lambda sign were identified by transvaginal ultrasonography at 9 weeks’ gestational age. b An obvious lambda sign was identified, via transabdominal ultrasonography at 17 weeks’ gestation.
chorionic twins. In this case, the chorionicity and zygosity were ultimately found to be monochorionic and monozygotic after DNA typing each fetus. The lambda sign, which is the triangular tissue projection extending from the base of the intertwine membrane, has been commonly used for antenatal ultrasonographic chorionicity determination in twin pregnancies. The determination of chorionicity using the lambda sign has been regarded as the most reliable during only the first trimester, because it becomes gradually more difficult to detect as gestation time increases [1, 2]. The sensitivity and the specificity for the lambda sign in combination with other ultrasound markers, including fetal sex and number of placental masses before 14 weeks’ gestation, are approximately 89.9–100.0 and 97.4–99.8%, respectively [3–5].
However, several cases have been reported that are inconsistent with the accepted clinical usefulness of ultrasound markers for determining chorionicity. The cases of monochorionic diamniotic (MCDA) twins with separate placental masses [6] and sex-discordant monochorionic twins, indicating the dizygotic MCDA condition, were also reported [7]. These phenomena present a dilemma when determining the chorionicity of twin pregnancies. The present case is similarly problematic in terms of using the lambda sign after the first trimester. We should be aware of the potential ambiguity of ultrasonographic diagnosis of chorionicity in twin pregnancies as gestation progresses. Furthermore, in cases of twin pregnancies where a marked difference in amniotic fluid volume appears, the possibility of MCDA should be taken into account.
References
156
4 Lee YM, Cleary-Goldman J, Thaker HM, Simpson LL: Antenatal sonographic prediction of twin chorionicity. Am J Obstet Gynecol 2006;195:863–867. 5 Dias T, Arcangeli T, Bhide A, Napolitano R, Mahsud-Dornan S, Thilaganathan B: Firsttrimester ultrasound determination of chorionicity in twin pregnancy. Ultrasound Obstet Gynecol 2011;38:530–532.
Fetal Diagn Ther 2015;37:154–156 DOI: 10.1159/000367969
6 Lopriore E, Sueters M, Middeldorp JM, Klumper F, Oepkes D, Vandenbussche FP: Twin pregnancies with two separate placental masses can still be monochorionic and have vascular anastomoses. Am J Obstet Gynecol 2006;194:804–808. 7 Souter VL, Kapur RP, Nyholt DR, Skogerboe K, Myerson D, Ton CC, Opheim KE, Easterling TR, Shields LE, Montgomery GW, Glass IA: A report of dizygous monochorionic twins. N Engl J Med 2003;349:154–158.
Yamashita/Ishii/Hidaka/Yonetani/ Hayashi/Takeuchi/Mitsuda
Downloaded by: Dahlgree Med. Library, Goergetown Univ. 141.161.91.14 - 5/23/2015 8:09:54 AM
1 Bessis R, Papiernik E: Echographic imagery of amniotic membranes in twin pregnancies. Prog Clin Biol Res 1981;69A:183–187. 2 Sepulveda W: Chorionicity determination in twin pregnancies: double trouble. Ultrasound Obstet Gynecol 1997;10:79–81. 3 Menon DK: A retrospective study of the accuracy of sonographic chorionicity determination in twin pregnancies. Twin Res Hum Genet 2005;8:259–261.
