eMedicine Specialties > Obstetrics and Gynecology > Obstetrical Complications

Twin-to-Twin Transfusion Syndrome

Author: Terence Zach, MD, Department Vice-Chair, Professor, Department of Pediatrics, Section of Newborn Medicine, Creighton University
Coauthor(s): Michael J Barsoom, MD, Assistant Professor of Obstetrics and Gynecology, Director of Perinatal Ultrasound, Creighton University Medical Center
Contributor Information and Disclosures

Updated: Aug 24, 2007

Introduction

Background

Twin-to-twin transfusion syndrome (TTTS) is the result of an intrauterine blood transfusion from one twin (donor) to another twin (recipient). TTTS only occurs in monozygotic (identical) twins with a monochorionic placenta. The donor twin is often smaller with a birth weight 20% less than the recipient's birth weight. The donor twin is often anemic and the recipient twin is often plethoric with hemoglobin differences greater than 5 g/dL.

Pathophysiology

TTTS is the result of transfusion of blood from one fetal twin to another twin. The blood transfusion from the donor twin to the recipient twin occurs through placental vascular anastomoses. The most common vascular anastomosis is a deep, artery-to-vein anastomosis through a shared placental cotyledon.

TTTS is a specific complication of monozygotic twins with monochorionic placentation. Although monozygotic twins can have dichorionic placentation, such twins are not at risk for TTTS. Monozygotic twins with monochorionic, diamniotic placentation (see Media File 1) or monochorionic, monoamniotic placentation are at risk for TTTS (see Media File 2).
 
The clinical features of TTTS are the result of hypoperfusion of the donor twin and hyperperfusion of the recipient twin.

The donor twin becomes hypovolemic and oliguric or anuric. Oligohydramnios develops in the amniotic sac of the donor twin. Profound oligohydramnios can result in the stuck twin phenomenon in which the twin appears in a fixed position against the uterine wall. Ultrasonography may fail to visualize the fetal bladder because of absent urine.

The recipent twin becomes hypervolemic and polyuric. Polyhydramnios develops in the amniotic sac of the recipient twin.

Either twin can develop hydrops fetalis. The donor twin can become hydropic because of anemia and high-output heart failure. The recipient twin can become hydropic because of hypervolemia. The recipient twin can also develop hypertension, hypertrophic cardiomegaly, disseminated intravascular coagulation, and hyperbilirubinemia after birth.

Frequency

United States

Monozygotic twins occur in 3-5 per 1000 pregnancies. Monozygotic twins can be monochorionic or dichorionic. Approximately 75% of monozygotic twins are monochorionic. Only monochorionic twins are at risk for TTTS. TTTS occurs in 5-38% of monochorionic twins.

Mortality/Morbidity

Severe TTTS has a 60-100% fetal or neonatal mortality rate. Mild-to-moderate TTTS is frequently associated with premature delivery. Fetal demise of one twin is associated with neurologic sequelae in 25% of surviving twins. Fetal blood pressure instability can lead to brain ischemia in either the donor or recipient twin. Ischemia of the fetal brain can result in periventricular leukomalacia, porencephaly, microcephaly and cerebral palsy. The more premature the twins are at birth, the higher the incidence of postnatal morbidity and mortality.

Sex

TTTS only occurs in same sex, monozygotic twins with monochorionic placentation.

Clinical

History

  • Women with twin pregnancies who develop twin-to-twin transfusion syndrome (TTTS) frequently complain of a rapidly enlarging abdomen over 2-3 weeks as polyhydramnios develops in the amniotic sac of the recipient twin.
  • Other complaints include preterm labor and premature rupture of membranes.

Physical

TTTS should be considered in a pregnant woman carrying twins if she develops a rapidly increasing fundal height. After birth, TTTS can be considered if the twins are monozygotic, and significant differences occur in the size or appearance of the twins. 

  • Donor twin
    • Small for gestational age - More than 20% smaller than recipient twin
    • Pallor
    • Poor peripheral perfusion
  • Recipient twin
    • Large for gestational age - More than 20% larger than donor twin
    • Plethoric and ruddy
    • Jaundice
  • Hydrops fetalis can be present in either twin in TTTS. These infants have subcutaneous edema, a distended abdomen, and respiratory distress.

Causes

TTTS occurs in monozygotic, monochorionic twin pregnancies when an anastomosis between placental vasculature exists.

More on Twin-to-Twin Transfusion Syndrome

Overview: Twin-to-Twin Transfusion Syndrome
Differential Diagnoses & Workup: Twin-to-Twin Transfusion Syndrome
Treatment & Medication: Twin-to-Twin Transfusion Syndrome
Follow-up: Twin-to-Twin Transfusion Syndrome
Multimedia: Twin-to-Twin Transfusion Syndrome
References
[ CLOSE WINDOW ]

References

  1. Quintero RA, Morales WJ, Allen MH, Bornick PW, Johnson PK, Kruger M. Staging of twin-twin transfusion syndrome. J Perinatol. Dec 1999;19(8 Pt 1):550-5. [Medline].

  2. Brackley KJ, Kilby MD. Twin-twin transfusion syndrome. Hosp Med. Jun 1999;60(6):419-24. [Medline].

  3. Denbow ML, Battin MR, Cowan F, et al. Neonatal cranial ultrasonographic findings in preterm twins complicated bysevere fetofetal transfusion syndrome. Am J Obstet Gynecol. Mar 1998;178(3):479-83. [Medline].

  4. Duncan KR. Twin-to-twin transfusion: update on management options and outcomes. Curr Opin Obstet Gynecol. Dec 2005;17(6):618-22. [Medline].

  5. Elliot JP. Amniocentesis for twin-twin transfusion syndrome. Contemp Ob Gyn. 1992;37:30-47.

  6. [Best Evidence] Fox C, Kilby MD, Khan KS. Contemporary treatments for twin-twin transfusion syndrome. Obstet Gynecol. Jun 2005;105(6):1469-77. [Medline].

  7. Huber A, Diehl W, Bregenzer T, Hackelöer BJ, Hecher K. Stage-related outcome in twin-twin transfusion syndrome treated by fetoscopic laser coagulation. Obstet Gynecol. Aug 2006;108(2):333-7. [Medline].

  8. Machin GA, Keith LG. Can twin-to-twin transfusion syndrome be explained, and how is it treated?. Clin Obstet Gynecol. Mar 1998;41(1):104-13. [Medline].

  9. Milner R, Crombleholme TM. Troubles with twins: fetoscopic therapy. Semin Perinatol. Dec 1999;23(6):474-83. [Medline].

  10. Sueters M, Middeldorp JM, Lopriore E, Oepkes D, Kanhai HH, Vandenbussche FP. Timely diagnosis of twin-to-twin transfusion syndrome in monochorionic twin pregnancies by biweekly sonography combined with patient instruction to report onset of symptoms. Ultrasound Obstet Gynecol. Oct 2006;28(5):659-64. [Medline].

  11. Taylor MJ, Govender L, Jolly M, Wee L, Fisk NM. Validation of the Quintero staging system for twin-twin transfusion syndrome. Obstet Gynecol. Dec 2002;100(6):1257-65. [Medline].

  12. Yamamoto M, Ville Y. Recent findings on laser treatment of twin-to-twin transfusion syndrome. Curr Opin Obstet Gynecol. Apr 2006;18(2):87-92. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

twin-to-twin transfusion syndrome, TTTS, stuck twin syndrome, stuck twin phenomenon, feto-fetal transfusion syndrome, interfetal transfusion syndrome, polyhydramnios, oligohydramnios, hydrops fetalis, thoracocentesis, pericardiocentesis, paracentesis, placental vascular anastomoses, anemia, plethora, polycythemia, hypocalcemia, renal dysfunction, thrombocytopenia, hyperbilirubinemia, intraventricular hemorrhage, periventricular leukomalacia, myocardial dysfunction, myocardial hypertrophy, valvular insufficiency, pericardial effusion, abnormal renal echogenicity, hypoxic-ischemic cortical necrosis, ascites, pleural effusions, cardiomegaly

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Terence Zach, MD, Department Vice-Chair, Professor, Department of Pediatrics, Section of Newborn Medicine, Creighton University
Terence Zach, MD is a member of the following medical societies: American Academy of Pediatrics, American Medical Association, and Nebraska Medical Association
Disclosure: Nothing to disclose.

Coauthor(s)

Michael J Barsoom, MD, Assistant Professor of Obstetrics and Gynecology, Director of Perinatal Ultrasound, Creighton University Medical Center
Michael J Barsoom, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, and Society for Maternal-Fetal Medicine
Disclosure: Nothing to disclose.

Medical Editor

Robert K Zurawin, MD, Associate Professor, Director of Fellowship Programs, Minimally Invasive Surgery, Department of Obstetrics and Gynecology, Baylor College of Medicine; Chief of Gynecology, Texas Children's Hospital
Robert K Zurawin, MD is a member of the following medical societies: American Association of Gynecologic Laparoscopists, American College of Obstetricians and Gynecologists, American Society for Reproductive Medicine, Association of Professors of Gynecology and Obstetrics, Central Association of Obstetricians and Gynecologists, Harris County Medical Society, North American Society for Pediatric and Adolescent Gynecology, and Texas Medical Association
Disclosure: Johnson and Johnson Honoraria Speaking and teaching; Conceptus Honoraria Speaking and teaching

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

CME Editor

Frederick B Gaupp, MD, Consulting Staff, Department of Family Practice, Assumption Community Hospital
Frederick B Gaupp, MD is a member of the following medical societies: American Academy of Family Physicians
Disclosure: Nothing to disclose.

Chief Editor

David Chelmow, MD, Professor of Obstetrics and Gynecology, Tufts University School of Medicine; Program Director, Tufts University Affiliated Hospitals OB/GYN Residency Program; Chair, Tufts University Health Sciences Campus Institutional Review Board
David Chelmow, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Medical Association, Association of Professors of Gynecology and Obstetrics, Massachusetts Medical Society, Phi Beta Kappa, Sigma Xi, Society for Gynecologic Investigation, and Society for Medical Decision Making
Disclosure: Nothing to disclose.

RELATED MEDSCAPE ARTICLES
Articles
 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.