Monochorionic Twins and Twin Transfusion Syndrome

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1 Monochorionic Twins and Twin Transfusion Syndrome
Emanuel P. Gaziano, M.D. Minnesotal Perinatal Physicians Abbott Northwestern Hospital, Minneapolis Professor, Department of Ob/Gyn University of Minnesota Emanuel Gaziano, MD Multiple Gestation Pregnancies

2 Multiple Gestations Twins occurrence Ovulation induction increases:
1/90 Natural 1/45 ART Ovulation induction increases: Twins rate 4X Triplet or higher 72X MZ twins 3.8X Twins have a natural occurrence of about 1 in 90 In early 90s the ART increased that rate to about 1 in 45 Ovulation induction not only increases the number of twin pregnancies it also increases the number of multiples It also increase the MZ twinining – these are your mono chorionic groups – higher complications Logerot-Lebrun. Contracept Fertil Sex:1993;21:362 Luke B, Martin, JA. Clinical Obstetrics and Gynecology 47:1, 2004

3 Multiple Gestations Membranes Placental symmetry Blood vessels
Type of placenta determines frequency and severity of complications In terms of ultrasound we have to be thinking of membranes placental symmetry & blood vessels In multiple gestation amniotic fluid level is important however, the first issue for the examiner should always be to determine the chrionocity (# of placenta)

4 What Type of Twining Event Has Occurred?

5 Dizygotic or “Fraternal” Twin “arise from two fertilized ova”
~ 2/3 of spontaneous twin pregnancies are dizygotic Frequently affected by Maternal ethnicity Blacks highest in Africa > white intermediate in USA & Europe > Asians lowest in Japan & China Maternal central gonadotropin levels – high FSH levels Maternal Age > 35 years old Multi-parity Maternal genetics Previous / family history of dizygotic twins Ovulation induction therapy Occurs in variable rates…..

6 Dizygotic or “Fraternal” Twin “arise from two fertilized ova”
Dichorionic (2 placentas) & Diamniotic Membrane: 4 layers (2 chorion & 2 amnion)

7

8 Monozygotic or “Identical” Twin “arise from one fertilized ovum”
Constant rate across population – 3-5 / 1000 ~ 1/3 natural conception Can occur in ART Variable chorionicity Variable amnionicity Variable risk Depends on when the zygote (fertilized ovum) divides Occurs in a constant rate Depending on when the fertilized egg splits into two, we can get different forms of placentation and amnionicity

9 Monozygotic or “Identical” Twin “arise from one fertilized ovum”
Monochorionic & Diamniotic Dividing membrane: 2 layers of amnion with no interposing chorion

10 Placentation & Chorionicity

11 Placentation & Chorionicity Relative Risks
Division of zygote Frequency Placentation Risk Mortality Rate < 3 days after fertilization 25% Di – Di 10% 4 – 8 days 75% Mono – Di 9 – 13 days 2% Mono – Mono 50% > 13 days Rare Conjoined 99% Division of zygote within the first 3 days after fertilization results in dichorionic-diamniotic placentation.

12 Twin Gestations & Relative Risks
Diamniotic-Dichorionic Age risk for aneuploidy higher than singleton rate Early loss greater than singleton Greater congenital anomaly rate compared to singleton Diamniotic-Monochorionic Age risk for aneuploidy same as singleton rate Early loss rate greater than Di-Di twins Greater congenital anomaly rate compared to Di-Di twins

13 Chorionicity & Amnionicity
DC-DA Thick membrane around each sac MC-DA Thick membrane around periphery, but thin membrane between sacs MC-MA Thick membrane around periphery and no visible membrane between sacs

14 Chorionicity & Amnionicity
DC-DA Thick membrane around each sac MC-DA Thick membrane around periphery, but thin membrane between sacs MC-MA Thick membrane around periphery and no visible membrane between sacs

15 Chorionicity & Amnionicity
DC-DA Thick membrane around each sac MC-DA Thick membrane around periphery, but thin membrane between sacs MC-MA Thick membrane around periphery and no visible membrane between sacs

16 Implications of Early Chorionicity Determination
The rate of miscarriage & perinatal death in monochorionic twins > dichorionic twins Death of a monochorionic fetus is associated with a high chance of sudden death or severe neurologic impairment in the co-twin Genetic disorders & chromosomal abnormalities is dependent on chorionicity Management of pregnancy 1. In monochorionic twins the rate of miscarriage & perinatal death are much higher than in dichorionic twins. 3. In monochorionic twin pregnancies, when undertaking invasive diagnostic tests such as amniocentesis or CVS, it may be unnecessary to sample both fetuses since they are monozygotic and, therefore, have identical genetic compositions. 4. In the management of twin pregnancy discordant for a major fetal defect, one of the options is selective feticide. But in monochorionic twins this procedure should be avoided, otherwise both fetuses could die or the survivor could suffer severe neurologic impairment.

17 Complications

18 General Risks of Multiple Pregnancy
Fetal Complications Preterm births Growth restriction Early post-maturity Fetal anomalies Maternal Complications Preeclampsia Placenta abruption Placenta previa Pre & postpartum hemorrhage Monozygotic twins  anomalies Monochorionic twins TTTS Acardiac twin Monoamniotic twins Cord entanglement Conjoining Death of a twin

19 Monozygotic Twins Congenital anomalies – structural
Twins - 2x singletons Monozygotic - 2x dizygotic 80 to 90 % of structural malformations are discordant

20 Monoamniotic Twins Cord entanglement Conjoining Death of a twin

21 Monoamniotic Twins The umbilical cords usually insert near one another
The placental vessels typically have large-caliber anastomoses between them TTS is less common because imbalance in the two circulations could not be sustained for long period

22 Monoamniotic Twins MC-MA twins have a further increased incidence of entangled cords

23 Conjoined Twins form when a single fertilized egg fails to divide completely to create two distinct individuals 1 in 50,000 to 1 in 200,000

24 Twin Reversed Arterial Perfusion “Acardiac Twin”
1% of MC Pregnancies 1 in 35,000 Pregnancies Acardiac twin perfused by deoxygenated blood from “pump” twin Flow in umbilical artery of abnormal twin is toward fetus

25 Twin Reversed Arterial Perfusion “Acardiac Twin”
Delayed cardiac function of one twin

26 Twin Reversed Arterial Perfusion “Acardiac Twin”
Commonly edematous, cystic appearing mass (similar to cystic hygroma) Absent cranium, cervical spine and upper extremities No cardiac structures or activity Lower half of body better developed

27 Twin Reversed Arterial Perfusion “Acardiac Twin”

28 Twin Twin Transfusion A syndrome occurring in MC pregnancies due to artery to vein anastomoses in which the donor twin partially perfuses the recipient twin. Also known as TTTS or TOPS (Twins oligohydramnios, polyhydramnios sequence.) Emanuel Gaziano, MD Multiple Gestation Pregnancies

29 Twin-twin Transfusion Syndrome
Outcome: Without treatment, mortality is % Neurological morbidity: 37% If one fetus dies, there is a 25% risk of severe neurologic impairment probably due to hypotension, hypoxia or thromboembolism Adegbite AJOBG 190:156, 2004 Turrentine et al. Am J Perinatol 13:351,1996 Emanuel Gaziano, MD Multiple Gestation Pregnancies

30 Outcome Less than 28 weeks survival 21% irrespective of method of management including decompression amniocentesis or tocolytics. Gondoulin W, et al. 1990, Obstet Gynecol 75:214. Emanuel Gaziano, MD Multiple Gestation Pregnancies

31 Frequency About 15% of monochorionic twins will show some evidence of twin to twin transfusion syndrome Emanuel Gaziano, MD Multiple Gestation Pregnancies

32 Frequency TTTS Twin Gestation Diamniotic Dichorionic
(70-80%) TTTS Rare Diamniotic monochorionic (20-30%) MC-TTS (6-15%) MC-non TTS (85-94%) Emanuel Gaziano, MD Multiple Gestation Pregnancies

33 Etiology MC Twins Vascular anastomoses Unequal placental sharing
Abnormal size of umbilical cord Velamentous insertion of cord Emanuel Gaziano, MD Multiple Gestation Pregnancies

34 4 to 7 Days after fertilization
Emanuel Gaziano, MD Multiple Gestation Pregnancies 4 to 7 Days after fertilization

35 Vascular arrangement TTTS
Emanuel Gaziano, MD Multiple Gestation Pregnancies

36 Surface Vessels on Chorionic Plate
Artery to vein anastomoses primary defect Actually fewer balanced anastomoses Nose to nose A-V connections Gaziano E, Harkness, U. Doppler Velocimetry and Multiple Gestation.In Doppler Ultrasound in Obstetrics and Gynecology, D. Maulik, ed. 2005 Emanuel Gaziano, MD Multiple Gestation Pregnancies

37 Contrast Medium Demonstrating Vascular Anastomoses in MC Twins
Emanuel Gaziano, MD Multiple Gestation Pregnancies

38 Etiology: Hemoglobin Differences
Mean hemoglobin difference is 4.8 gr/dl. In cordocentesis studies any range of hemoglobin differences have been observed even in the presence of hydrops in the recipient. Neonatal criteria is more rigid for diagnosis requiring 5.0 gr/dl difference Gaziano E, Harkness, U. Doppler Velocimetry and Multiple Gestation.In Doppler Ultrasound in Obstetrics and Gynecology, D. Maulik, ed. 2005 Emanuel Gaziano, MD Multiple Gestation Pregnancies

39 Diagnosis: 1st Trimester
NT in DiMo twins If NT abnormal measure DV Abnormal NT + Abnormal DV predicts TTTS Sebire Human Reproduction, Vol.15, No. 9, , September 2000 Emanuel Gaziano, MD Multiple Gestation Pregnancies

40 20 week scan TWIN A: HC=23 1/7ths Wks TWIN B: HC=20 6/7ths Wks
TWIN A: AC=23 4/7ths Wks TWIN B: HC=19 5/7ths Wks Emanuel Gaziano, MD Multiple Gestation Pregnancies

41 20 week scan Emanuel Gaziano, MD Multiple Gestation Pregnancies

42 20 week scan TWIN B: Cord Insertion TWIN B Umbilical Artery Doppler
Emanuel Gaziano, MD Multiple Gestation Pregnancies

43 Ultrasound of TTTS Features of MC Placenta Fused placenta
Thin dividing membrane Dissimilar AF volumes Emanuel Gaziano, MD Multiple Gestation Pregnancies

44 Sonographic Signs TTTS
Oligohydramnios Donor sac <2 cm Hydramnios Recipient sac >8cm Growth discordance Thin dividing membrane Same gender pair Blickstein I. Obstet Gynecol 1990;76:714-22 Emanuel Gaziano, MD Multiple Gestation Pregnancies

45 Ultrasound of TTTS Emanuel Gaziano, MD Multiple Gestation Pregnancies

46 TTTS Emanuel Gaziano, MD Multiple Gestation Pregnancies

47 Ultrasound TTS Assess cord insertion site for each twin
Emanuel Gaziano, MD Multiple Gestation Pregnancies

48 Ultrasound TTTS Assess for velamentous insertion Emanuel Gaziano, MD
Multiple Gestation Pregnancies

49 Ultrasound TTTS Assess Placental Mass Emanuel Gaziano, MD
Multiple Gestation Pregnancies

50 Other sonographic signs TTTS
Echogenic bowel Cardiac: enlargement, tricuspid regurgitation, ROF obstruction Pulmonary artery calcification Emanuel Gaziano, MD Multiple Gestation Pregnancies

51 Doppler In TTTS Initial studies: CW no difference in Doppler values (Trudinger) Abnormal UA Doppler values may be seen in either donor or recipient but more common in Donor. Abnormal Doppler values predict adverse outcomes. Role for Doppler in Staging of TTTS Abnormal venous values seen in TTTS Gaziano E, Harkness, U. Doppler Velocimetry and Multiple Gestation. In Doppler Ultrasound in Obstetrics and Gynecology, D. Maulik, ed. 2005 Emanuel Gaziano, MD Multiple Gestation Pregnancies

52 Abnormal Doppler also predicts poor outcome in TTTS
Umbilical artery PI Doppler difference is greater in MC twins who are destined to develop hydrops. Poor prognostic factors in TTTS: zero or REDF in umbilical artery Doppler Abnormal venous Doppler Absence of artery to artery anastomoses Taylor et al, 2000 Am J Obstet Gynecol 183:1023 Emanuel Gaziano, MD Multiple Gestation Pregnancies

53 Extreme Cases of TTTS When cord Hb differences are >5
Doppler values in Donor and Recipient may be similar Emanuel Gaziano, MD Multiple Gestation Pregnancies

54 Quintero Staging of twin-twin transfusion syndrome
Stage I Amniotic fluid differences Stage II Absence of bladder Stage III Critically abnormal Dopplers Stage IV Presence of ascites or frank hydrops Stage V Demise of either fetus. J Perinatol 19: Emanuel Gaziano, MD Multiple Gestation Pregnancies

55 Quintero Staging of twin-twin transfusion syndrome
Stage II Diastolic flow in UA and forward flow in the DV Stage III Zero or AED flow in UA and reverse flow in DV J Perinatol 19: Emanuel Gaziano, MD Multiple Gestation Pregnancies

56 Twin-twin Transfusion Syndrome
Emanuel Gaziano, MD Multiple Gestation Pregnancies

57 Options for Treatment Septostomy Amnioreduction
Laser separation of the circulations Feticide Emanuel Gaziano, MD Multiple Gestation Pregnancies

58 Options for Treatment Septostomy Separates the dividing membrane
Equalizes fluid pressure Usually small holes punctured in the dividing membrane Risk for cord entanglement Amnioreduction Reduce amniotic fluid volume in the recipient sac. Usually for Stage I or II Decompress when DVP >11 Decompress to normal range <DVP of 8 Risk: infection Emanuel Gaziano, MD Multiple Gestation Pregnancies

59 Technique similar to genetic amnio: larger needle and vacuum bottle.
Emanuel Gaziano, MD Multiple Gestation Pregnancies

60 Prospective randomized trial comparing amnioreduction to septostomy
Survival in each group was 65% No data on neurologic outcome Saade GR, Moise K, Dormar KA et al: Randomized trial of septostomy verses amnioreduction in the treatment of twin oligohydramnios polyhydramnios sequence (TOPS). American Journal of Obstetrics and Gynecology (abstr) 187: 3, 2003. Emanuel Gaziano, MD Multiple Gestation Pregnancies

61 DeLia 1995 N=26 Severe TTTS by Laser
Surviving fetuses were delivered for obstetric reasons at a mean of 32.2 weeks (range, 26 to 37 weeks). Fifty-three percent (28 of 53) of fetuses survived 96% (27 of 28) showed normal development at a mean of 35.8 months of follow-up (range, 1 to 68 months). DeLia JE, et al: Fetoscopic laser ablation of placental vessels in severe previable twin-twin transfusion syndrome. American Journal of Obstetrics and Gynecology 172:1202, 1995. Emanuel Gaziano, MD Multiple Gestation Pregnancies

62 Laser vs Amnioreduction
N=73 women were treated between 1995 and 1997 in one center by fetoscopic laser photocoagulation N=43 patients were treated at another center between 1992 and 1996 by serial amnioreduction. Hecher K, et al: Endoscopic laser surgery versus serial amniocentesis in the treatment of severe twin-twin transfusion syndrome. American Journal of Obstetrics and Gynecology 180:717, 1999. Emanuel Gaziano, MD Multiple Gestation Pregnancies

63 Hecher K, et al: Endoscopic laser surgery versus serial amniocentesis in the treatment of severe twin-twin transfusion syndrome. American Journal of Obstetrics and Gynecology 180:717, 1999 Emanuel Gaziano, MD Multiple Gestation Pregnancies

64 N=167 follow up to 3 years and 2months
Long-term neurodevelopmental outcome of children born after laser for severe TTTS N=167 follow up to 3 years and 2months 145 (86.8%) showed normal development, 12 infants (7.2%) showed minor neurologic abnormalities, 10 infants (6.0%) major neurologic abnormalities. Graef C. Am J Obstet Gynecol Feb;194(2):303-8. Emanuel Gaziano, MD Multiple Gestation Pregnancies

65 No difference in outcome for the former donors/recipients (P = .349)
Long-term neurodevelopmental outcome of children born after Laser for severe TTTS No difference in outcome for the former donors/recipients (P = .349) CONCLUSION: intrauterine laser coagulation seems to be the best treatment option for severe twin-twin transfusion syndrome. Graef C. Am J Obstet Gynecol Feb;194(2):303-8. Emanuel Gaziano, MD Multiple Gestation Pregnancies

66 Perinatal death rate higher when laser used for treatment of TTTS in Stage I and II (p=.02)
Emanuel Gaziano, MD Multiple Gestation Pregnancies Quintero et al, Am J Obstet Gynecol 2003;188:1333

67 Perinatal death rate lower when laser used for treatment of TTTS in Stage III and IV (p=.02)
Emanuel Gaziano, MD Multiple Gestation Pregnancies Quintero et al, Am J Obstet Gynecol 2003;188:1333

68 Two prospective randomized clinical trials
The Eurofetus trial in Europe The National-Institutes-of-Health-sponsored trial in the United States  Compare aggressive serial amnioreduction to fetoscopic laser photocoagulation. Emanuel Gaziano, MD Multiple Gestation Pregnancies

69 2011 NIH Trial The trial had uncovered higher mortality among recipient twins who received laser treatment. But overall, survival of one or both twins of the same pregnancy was no different between the two treatments. In addition, there was no difference between survival rates of donor twins and recipient twins. Emanuel Gaziano, MD Multiple Gestation Pregnancies

70 Cochrane Review Laser coagulation resulted in less overall death (48% vs. 59%) when compared with amnioreduction. The results suggest that endoscopic laser coagulation of anastomotic vessels should be considered in the treatment of all stages of TTTS to improve perinatal and neonatal outcome Emanuel Gaziano, MD Multiple Gestation Pregnancies

71 Treatment Summary Most studies show outcomes for laser separation superior to amnioreduction. Always exceptions due to the small placental mass and complications due to velamentous insertions in some MC pregnancies. Spontaneous improvement occurs in some cases (anastomoses change) Emanuel Gaziano, MD Multiple Gestation Pregnancies

72 Discordant Growth (AEDF)
Emanuel Gaziano, MD Multiple Gestation Pregnancies

73 Thank you! Emanuel Gaziano, MD Multiple Gestation Pregnancies