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Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy
G Model JOGOH 101694 No. of Pages 3
Journal of Gynecology Obstetrics and Human Reproduction xxx (2019) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Case Report
Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy Maëlig Abgrala , Jelena Martinovicb , Aurore Bonninb , Marie Houlliera , Marie Victoire Senata , Hanane Bouchghoula,* a b
Department of Gynecology and Obstetrics, AP-HP, Hôpital Bicêtre, Université Paris-Saclay, Le Kremlin - Bicêtre, France Department of Fetal Pathology, AP-HP, Hôpital Antoine Béclère, Clamart, France
A R T I C L E I N F O
A B S T R A C T
Article history: Available online xxx
Monochorionic pregnancies are associated with a higher risk of perinatal morbidity and mortality than dichorionic pregnancies. Early determination of chorionicity by an ultrasound exam between 11+0 and 14+0 weeks’ gestation (WG) is essential for the subsequent management of twin pregnancies. The presence of the T-sign is the most specific sign for determination of monochorionicity. During the second trimester, the presence of two distinct placental masses has a lower specificity in determining the chorionicity. We report here two cases of a monochorionic pregnancy with a bipartite placenta, suggesting that a placenta with two separate masses, each with a distinct cord insertion is not always indicative of a dichorionic pregnancy.’ © 2020 Elsevier Masson SAS. All rights reserved.
Keywords: Bipartite placenta Twin pregnancy Monochorionic Prenatal Chorionicity
Introduction Monochorionic pregnancies are associated with a higher risk of perinatal morbidity and mortality than dichorionic pregnancies [1]. Vascular anastomosis is an almost constant feature of monochorionic pregnancies and leads to specific complications such as twin-to-twin transfusion syndrome, twin anemia polycythemia sequence and selective intrauterine growth restriction [2]. Monochorionic twins should be followed up closely to improve the diagnosis and management of specific complications. Early determination of chorionicity by an ultrasound exam between 11+0 and 14+0 weeks’ gestation (WG) is essential for the subsequent management of twin pregnancies. The presence of the T-sign (direct binding of the two thin amniotic membranes) is consistent with the diagnosis of a monochorionic twin pregnancy, with a sensitivity of 100 % and a specificity of 99.8 % [3]. In the case of late pregnancy diagnosis, the determination of chorionicity is less accurate than at an earlier gestational age. The ultrasound signs described in the second trimester for the diagnosis of a dichorionic pregnancy, as the thickness of the membrane and the presence of
* Corresponding author at: Department of Obstetrics and Gynecology, AP-HP, Bicêtre, Hospital, 78, avenue du Général Leclerc, 94275 Le Kremlin-Bicêtre, Cedex, France. E-mail address: [email protected] (H. Bouchghoul).
two distinct placental masses, have a much lower specificity in determining the chorionicity [4]. Very few cases of monochorionic diamniotic pregnancies with two placental masses have been documented [5,6]. We report here two cases of a monochorionic pregnancy with a configuration anomaly consisting of two distinct placental masses. Case 1 A 31-year-old patient, gravida four para three, with a history of bariatric surgery, presented with a spontaneous twin pregnancy. Ultrasound exam at 12+6 WG established the diagnosis of a monochorionic diamniotic twin pregnancy with the T-sign (Fig. 1). Ultrasound scans performed every two weeks showed two eutrophic fetuses, normal amniotic fluids and normal Doppler indices. Ultrasound at 23+0 WG showed two distinct placental masses without vasa previa (Fig. 2). The pregnancy was uncomplicated. At 34+4 WG, the patient went into spontaneous labor and delivered a twin A, a boy weighing 1870 g, Apgar 10-10, hemoglobin 13.9 g/dL, and a twin B, a boy weighing 1980 g, Apgar 8–10, hemoglobin 13.6 g/dL. Macroscopic analysis of the placenta showed two distinct placental masses each with a marginal cord insertion 15 cm apart and interconnected by a 30 mm membrane (Fig. 3a). The placental mass of twin A was 230 g with chorionic plate measuring 17 cm. The placental mass of twin B was 380 g and its chorionic plate measured 16 cm. Vessels were visualized running through the membranes between the two placental
http://dx.doi.org/10.1016/j.jogoh.2020.101694 2468-7847/© 2020 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: M. Abgral, et al., Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy, J Gynecol Obstet Hum Reprod (2020), https://doi.org/10.1016/j.jogoh.2020.101694
G Model JOGOH 101694 No. of Pages 3
2
M. Abgral et al. / J Gynecol Obstet Hum Reprod xxx (2019) 101694
Case 2
Fig. 1. Ultrasound at 12+6 weeks gestations showing twin pregnancy with a characteristic T sign.
masses. Vascular injections with colored dyes showed two large superficial anastomoses: an arterioarterial one and a venovenous one (Fig. 3b). Histological analysis of the interamniotic membrane found no interposition of the chorion in interamniotic membranes, confirming the diagnosis of a monochorionic diamniotic pregnancy.
A 36-year-old patient, gravida two nullipara, with a history of Hodgkin's disease and one abortion, presented with a spontaneous monochorionic twin pregnancy, diagnosed at 12+1 WG on ultrasound exam. At 19+1 WG, she was referred to the prenatal diagnosis center for a Quintero stage II twin-to-twin transfusion syndrome (TTS), which was resolved by selective fetoscopic laser photocoagulation of the anastomosis at 19+1 WG completed by the Solomon technique. The pregnancy was marked by cholestasis at 31+2 WG which was treated with ursodeoxycholic acid. Ultrasound scans performed every two weeks showed two eutrophic fetuses, normal amniotic fluids and normal Doppler indices. No brain abnormalities were seen on fetal cerebral MRI at 32+0 WG. Labor was induced by cervical ripening at 36+3 WG. The patient delivered vaginally a twin A, a girl weighing 1990 g, Apgar 7–10, hemoglobin 15.7 g/dL, and a twin B, a girl weighing 1980 g, Apgar 5–10, hemoglobin 13.7 g/dL. Macroscopic analysis showed a multilobed placenta with a vasa previa covering an interconnecting membrane (Fig. 4). An aberrant cotyledon was in contact with the placental mass of twin B. This configuration had not been detected by fetoscopy or ultrasound. The placental mass of twins A and B was 308 g and 316 g, respectively. Cord insertions were marginal for twin A and velamentous for twin B, with a distance of 14 cm between the two cords. No vascular anastomoses were identified between the two circulations. Vascular injections with colored dyes were not possible because
Fig. 2. Ultrasound at 23+3 weeks gestations: presence of two distinct placental masses. a: On the right side an area without placenta (white asterisk) between the placental mass of twin A (TA) and the placental mass of twin B (TB). b: On the left side an area without placenta (white asterisk) between the placental mass of twin A (TA) and the placental mass of twin B (TB).
Fig. 3. a: Placental analysis: two placental masses with marginal cord insertions on each mass (placental mass of twin A on the right and placental mass of twin B on the left). b: Fetal placental surface after vascular injections (veins are colored by red dye, arteries by blue dye): presence of large venovenous anastomosis (red arrow) and arterioarterial anastomosis (blue arrow) running both as a vasa previa.
Please cite this article in press as: M. Abgral, et al., Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy, J Gynecol Obstet Hum Reprod (2020), https://doi.org/10.1016/j.jogoh.2020.101694
G Model JOGOH 101694 No. of Pages 3
M. Abgral et al. / J Gynecol Obstet Hum Reprod xxx (2019) 101694
Fig. 4. Placental analysis: multilobed placenta with marginal cord insertion for twin A (Donor) and velamentous cord insertion for twin B (Recipient) (placental mass of twin A on the left and placental mass of twin B on the right). An aberrant cotyledon (white asterisk) in contact with placental mass of twin B. Vasa previa covering membranes.
of placental damage. Histological analysis of the interamniotic membrane found no interposition of the chorion in interamniotic membranes. Discussion We report here two cases of monochorionic pregnancy with a multipartite placenta. Our findings suggest that two separate placental masses on ultrasound, each with its cord insertion, might not necessarily indicate a dichorionic pregnancy [5,6]. Nevertheless, contiguous placentas are observed in fifty percent of dichorionic placentas at ultrasound exam [7], which is in part explained by a transition state between monochorionic and dichorionic placentation [8]. Although the best time window to determine chorionicity is the first trimester, a set of criteria (the membrane layer count, the membrane’s thickness, the twin peak sign) should be preferred at a later stage of pregnancy for the diagnosis of monochorionicity [4]. The prevalence of monochorionic diamniotic pregnancies with a bipartite placenta is estimated at around 3 % [6]. Such pregnancies are characterized by vascular anastomosis, which could be unbalanced and lead to complications. However, their prognosis is poorly assessed as only four cases have been reported to date in the literature [5,6]. A double stillbirth and three cases of
3
twin-to-twin transfusion syndrome (two Quintero stage II and one III) including ours have been reported. Two pregnancies including our case were without complications. Fetoscopic laser coagulation of vascular anastomoses was performed for two of the cases of twin-to-twin transfusion syndrome and one amniodrainage was performed because of advanced gestational age. The risk of complications in these pregnancies is uncertain because of their low prevalence and rarity. Furthermore, because of the potential vasa previa and vascular anastomosis, there is an evident obstetrical risk of Benckiser hemorrhage for the two twins [9]. Patients should be advised accordingly, and the obstetrical management should take it into account. In conclusion, early diagnosis by first-trimester ultrasound is essential for the follow-up and management of twin pregnancies, in particular for monochorionic ones. In the case of co-occurrence of the T-sign and a bipartite placenta, careful attention should be paid to potential specific complications of monochorionic pregnancies. References [1] Lopriore E, Stroeken H, Sueters M, Meerman R-J, Walther F, Vandenbussche F. Term perinatal mortality and morbidity in monochorionic and dichorionic twin pregnancies: a retrospective study. Acta Obstet Gynecol Scand 2008;87:541–5, doi:http://dx.doi.org/10.1080/00016340802050668. [2] Hack KEA, Derks JB, Elias SG, Franx A, Roos EJ, Voerman SK, et al. Increased perinatal mortality and morbidity in monochorionic versus dichorionic twin pregnancies: clinical implications of a large Dutch cohort study. BJOG 2008;115:58–67, doi:http://dx.doi.org/10.1111/j.1471-0528.2007.01556.x. [3] Dias T, Arcangeli T, Bhide A, Napolitano R, Mahsud-Dornan S, Thilaganathan B. First-trimester ultrasound determination of chorionicity in twin pregnancy. Ultrasound Obstet Gynecol 2011;38:530–2, doi:http://dx.doi.org/10.1002/ uog.8956. [4] Shetty A, Smith APM. The sonographic diagnosis of chorionicity. Prenat Diagn 2005;25(9):735–9, doi:http://dx.doi.org/10.1002/pd.1266. [5] Kim K, Lage JM. Bipartite diamnionic monochorionic twin placenta with superficial vascular anastomoses: report of a case. Hum Pathol 1991;22(5):501– 3, doi:http://dx.doi.org/10.1016/0046-8177(91)90138-F. [6] Lopriore E, Sueters M, Middeldorp JM, Klumper F, Oepkes D, FPHA V. Twin pregnancies with two separate placental masses can still be monochorionic and have vascular anastomoses. Am J Obstet Gynecol 2006;196(2):159.e1–5, doi: http://dx.doi.org/10.1016/j.ajog.2005.09.015. [7] Loos RJ, Derom C, Derom R, Vlietinck R. Birthweight in liveborn twins: the influence of the umbilical cord insertion and fusion of placentas. BJOG 2001;108:943–8. [8] Benirschke K. Major pathologic features of the placenta, cord and membranes. 1965. [9] Swank ML, Garite TJ, Maurel K, Das A, Perlow JH, Combs CA, et al. Vasa previa: diagnosis and management. Am J Obstet Gynecol 2016;215:223, doi:http://dx. doi.org/10.1016/j.ajog.2016.02.044 e1-6.
Please cite this article in press as: M. Abgral, et al., Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy, J Gynecol Obstet Hum Reprod (2020), https://doi.org/10.1016/j.jogoh.2020.101694
Journal of Gynecology Obstetrics and Human Reproduction xxx (2019) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Case Report
Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy Maëlig Abgrala , Jelena Martinovicb , Aurore Bonninb , Marie Houlliera , Marie Victoire Senata , Hanane Bouchghoula,* a b
Department of Gynecology and Obstetrics, AP-HP, Hôpital Bicêtre, Université Paris-Saclay, Le Kremlin - Bicêtre, France Department of Fetal Pathology, AP-HP, Hôpital Antoine Béclère, Clamart, France
A R T I C L E I N F O
A B S T R A C T
Article history: Available online xxx
Monochorionic pregnancies are associated with a higher risk of perinatal morbidity and mortality than dichorionic pregnancies. Early determination of chorionicity by an ultrasound exam between 11+0 and 14+0 weeks’ gestation (WG) is essential for the subsequent management of twin pregnancies. The presence of the T-sign is the most specific sign for determination of monochorionicity. During the second trimester, the presence of two distinct placental masses has a lower specificity in determining the chorionicity. We report here two cases of a monochorionic pregnancy with a bipartite placenta, suggesting that a placenta with two separate masses, each with a distinct cord insertion is not always indicative of a dichorionic pregnancy.’ © 2020 Elsevier Masson SAS. All rights reserved.
Keywords: Bipartite placenta Twin pregnancy Monochorionic Prenatal Chorionicity
Introduction Monochorionic pregnancies are associated with a higher risk of perinatal morbidity and mortality than dichorionic pregnancies [1]. Vascular anastomosis is an almost constant feature of monochorionic pregnancies and leads to specific complications such as twin-to-twin transfusion syndrome, twin anemia polycythemia sequence and selective intrauterine growth restriction [2]. Monochorionic twins should be followed up closely to improve the diagnosis and management of specific complications. Early determination of chorionicity by an ultrasound exam between 11+0 and 14+0 weeks’ gestation (WG) is essential for the subsequent management of twin pregnancies. The presence of the T-sign (direct binding of the two thin amniotic membranes) is consistent with the diagnosis of a monochorionic twin pregnancy, with a sensitivity of 100 % and a specificity of 99.8 % [3]. In the case of late pregnancy diagnosis, the determination of chorionicity is less accurate than at an earlier gestational age. The ultrasound signs described in the second trimester for the diagnosis of a dichorionic pregnancy, as the thickness of the membrane and the presence of
* Corresponding author at: Department of Obstetrics and Gynecology, AP-HP, Bicêtre, Hospital, 78, avenue du Général Leclerc, 94275 Le Kremlin-Bicêtre, Cedex, France. E-mail address: [email protected] (H. Bouchghoul).
two distinct placental masses, have a much lower specificity in determining the chorionicity [4]. Very few cases of monochorionic diamniotic pregnancies with two placental masses have been documented [5,6]. We report here two cases of a monochorionic pregnancy with a configuration anomaly consisting of two distinct placental masses. Case 1 A 31-year-old patient, gravida four para three, with a history of bariatric surgery, presented with a spontaneous twin pregnancy. Ultrasound exam at 12+6 WG established the diagnosis of a monochorionic diamniotic twin pregnancy with the T-sign (Fig. 1). Ultrasound scans performed every two weeks showed two eutrophic fetuses, normal amniotic fluids and normal Doppler indices. Ultrasound at 23+0 WG showed two distinct placental masses without vasa previa (Fig. 2). The pregnancy was uncomplicated. At 34+4 WG, the patient went into spontaneous labor and delivered a twin A, a boy weighing 1870 g, Apgar 10-10, hemoglobin 13.9 g/dL, and a twin B, a boy weighing 1980 g, Apgar 8–10, hemoglobin 13.6 g/dL. Macroscopic analysis of the placenta showed two distinct placental masses each with a marginal cord insertion 15 cm apart and interconnected by a 30 mm membrane (Fig. 3a). The placental mass of twin A was 230 g with chorionic plate measuring 17 cm. The placental mass of twin B was 380 g and its chorionic plate measured 16 cm. Vessels were visualized running through the membranes between the two placental
http://dx.doi.org/10.1016/j.jogoh.2020.101694 2468-7847/© 2020 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: M. Abgral, et al., Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy, J Gynecol Obstet Hum Reprod (2020), https://doi.org/10.1016/j.jogoh.2020.101694
G Model JOGOH 101694 No. of Pages 3
2
M. Abgral et al. / J Gynecol Obstet Hum Reprod xxx (2019) 101694
Case 2
Fig. 1. Ultrasound at 12+6 weeks gestations showing twin pregnancy with a characteristic T sign.
masses. Vascular injections with colored dyes showed two large superficial anastomoses: an arterioarterial one and a venovenous one (Fig. 3b). Histological analysis of the interamniotic membrane found no interposition of the chorion in interamniotic membranes, confirming the diagnosis of a monochorionic diamniotic pregnancy.
A 36-year-old patient, gravida two nullipara, with a history of Hodgkin's disease and one abortion, presented with a spontaneous monochorionic twin pregnancy, diagnosed at 12+1 WG on ultrasound exam. At 19+1 WG, she was referred to the prenatal diagnosis center for a Quintero stage II twin-to-twin transfusion syndrome (TTS), which was resolved by selective fetoscopic laser photocoagulation of the anastomosis at 19+1 WG completed by the Solomon technique. The pregnancy was marked by cholestasis at 31+2 WG which was treated with ursodeoxycholic acid. Ultrasound scans performed every two weeks showed two eutrophic fetuses, normal amniotic fluids and normal Doppler indices. No brain abnormalities were seen on fetal cerebral MRI at 32+0 WG. Labor was induced by cervical ripening at 36+3 WG. The patient delivered vaginally a twin A, a girl weighing 1990 g, Apgar 7–10, hemoglobin 15.7 g/dL, and a twin B, a girl weighing 1980 g, Apgar 5–10, hemoglobin 13.7 g/dL. Macroscopic analysis showed a multilobed placenta with a vasa previa covering an interconnecting membrane (Fig. 4). An aberrant cotyledon was in contact with the placental mass of twin B. This configuration had not been detected by fetoscopy or ultrasound. The placental mass of twins A and B was 308 g and 316 g, respectively. Cord insertions were marginal for twin A and velamentous for twin B, with a distance of 14 cm between the two cords. No vascular anastomoses were identified between the two circulations. Vascular injections with colored dyes were not possible because
Fig. 2. Ultrasound at 23+3 weeks gestations: presence of two distinct placental masses. a: On the right side an area without placenta (white asterisk) between the placental mass of twin A (TA) and the placental mass of twin B (TB). b: On the left side an area without placenta (white asterisk) between the placental mass of twin A (TA) and the placental mass of twin B (TB).
Fig. 3. a: Placental analysis: two placental masses with marginal cord insertions on each mass (placental mass of twin A on the right and placental mass of twin B on the left). b: Fetal placental surface after vascular injections (veins are colored by red dye, arteries by blue dye): presence of large venovenous anastomosis (red arrow) and arterioarterial anastomosis (blue arrow) running both as a vasa previa.
Please cite this article in press as: M. Abgral, et al., Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy, J Gynecol Obstet Hum Reprod (2020), https://doi.org/10.1016/j.jogoh.2020.101694
G Model JOGOH 101694 No. of Pages 3
M. Abgral et al. / J Gynecol Obstet Hum Reprod xxx (2019) 101694
Fig. 4. Placental analysis: multilobed placenta with marginal cord insertion for twin A (Donor) and velamentous cord insertion for twin B (Recipient) (placental mass of twin A on the left and placental mass of twin B on the right). An aberrant cotyledon (white asterisk) in contact with placental mass of twin B. Vasa previa covering membranes.
of placental damage. Histological analysis of the interamniotic membrane found no interposition of the chorion in interamniotic membranes. Discussion We report here two cases of monochorionic pregnancy with a multipartite placenta. Our findings suggest that two separate placental masses on ultrasound, each with its cord insertion, might not necessarily indicate a dichorionic pregnancy [5,6]. Nevertheless, contiguous placentas are observed in fifty percent of dichorionic placentas at ultrasound exam [7], which is in part explained by a transition state between monochorionic and dichorionic placentation [8]. Although the best time window to determine chorionicity is the first trimester, a set of criteria (the membrane layer count, the membrane’s thickness, the twin peak sign) should be preferred at a later stage of pregnancy for the diagnosis of monochorionicity [4]. The prevalence of monochorionic diamniotic pregnancies with a bipartite placenta is estimated at around 3 % [6]. Such pregnancies are characterized by vascular anastomosis, which could be unbalanced and lead to complications. However, their prognosis is poorly assessed as only four cases have been reported to date in the literature [5,6]. A double stillbirth and three cases of
3
twin-to-twin transfusion syndrome (two Quintero stage II and one III) including ours have been reported. Two pregnancies including our case were without complications. Fetoscopic laser coagulation of vascular anastomoses was performed for two of the cases of twin-to-twin transfusion syndrome and one amniodrainage was performed because of advanced gestational age. The risk of complications in these pregnancies is uncertain because of their low prevalence and rarity. Furthermore, because of the potential vasa previa and vascular anastomosis, there is an evident obstetrical risk of Benckiser hemorrhage for the two twins [9]. Patients should be advised accordingly, and the obstetrical management should take it into account. In conclusion, early diagnosis by first-trimester ultrasound is essential for the follow-up and management of twin pregnancies, in particular for monochorionic ones. In the case of co-occurrence of the T-sign and a bipartite placenta, careful attention should be paid to potential specific complications of monochorionic pregnancies. References [1] Lopriore E, Stroeken H, Sueters M, Meerman R-J, Walther F, Vandenbussche F. Term perinatal mortality and morbidity in monochorionic and dichorionic twin pregnancies: a retrospective study. Acta Obstet Gynecol Scand 2008;87:541–5, doi:http://dx.doi.org/10.1080/00016340802050668. [2] Hack KEA, Derks JB, Elias SG, Franx A, Roos EJ, Voerman SK, et al. Increased perinatal mortality and morbidity in monochorionic versus dichorionic twin pregnancies: clinical implications of a large Dutch cohort study. BJOG 2008;115:58–67, doi:http://dx.doi.org/10.1111/j.1471-0528.2007.01556.x. [3] Dias T, Arcangeli T, Bhide A, Napolitano R, Mahsud-Dornan S, Thilaganathan B. First-trimester ultrasound determination of chorionicity in twin pregnancy. Ultrasound Obstet Gynecol 2011;38:530–2, doi:http://dx.doi.org/10.1002/ uog.8956. [4] Shetty A, Smith APM. The sonographic diagnosis of chorionicity. Prenat Diagn 2005;25(9):735–9, doi:http://dx.doi.org/10.1002/pd.1266. [5] Kim K, Lage JM. Bipartite diamnionic monochorionic twin placenta with superficial vascular anastomoses: report of a case. Hum Pathol 1991;22(5):501– 3, doi:http://dx.doi.org/10.1016/0046-8177(91)90138-F. [6] Lopriore E, Sueters M, Middeldorp JM, Klumper F, Oepkes D, FPHA V. Twin pregnancies with two separate placental masses can still be monochorionic and have vascular anastomoses. Am J Obstet Gynecol 2006;196(2):159.e1–5, doi: http://dx.doi.org/10.1016/j.ajog.2005.09.015. [7] Loos RJ, Derom C, Derom R, Vlietinck R. Birthweight in liveborn twins: the influence of the umbilical cord insertion and fusion of placentas. BJOG 2001;108:943–8. [8] Benirschke K. Major pathologic features of the placenta, cord and membranes. 1965. [9] Swank ML, Garite TJ, Maurel K, Das A, Perlow JH, Combs CA, et al. Vasa previa: diagnosis and management. Am J Obstet Gynecol 2016;215:223, doi:http://dx. doi.org/10.1016/j.ajog.2016.02.044 e1-6.
Please cite this article in press as: M. Abgral, et al., Two separate placental masses on ultrasound do not always indicate a dichorionic pregnancy, J Gynecol Obstet Hum Reprod (2020), https://doi.org/10.1016/j.jogoh.2020.101694