562

Vanishing Twin Syndrome: Pathogenesis & Diagnosis!

Vanishing twin syndrome has been recognized for the first time in 1945. The term is used when one of the fetuses disappears in a multiple pregnancy.

Vanishing Twin Syndrome

Table of Contents

What Is Vanishing Twin Syndrome?

The vanishing twin, or fetal resorption, is a fetus from a multiple pregnancy which dies in the uterus in then partially or completely absorbed by the mother or brother. The appearance of this phenomenon is sometimes called vanishing twin syndrome.

Fortunately, if the disappearance of the twin occurs in the first part of pregnancy, his tissues are absorbed by the surviving fetus or the mother`s body, and the pregnancy can evolve normally.

However, if the abortion of one of the fetuses occurs later, the doctors will keep the pregnancy under supervision because of the increased risk to complications, like premature birth, the obstruction of the birth canal or the death of the surviving fetus due to placental rupture or chorioamniotic separation.

Occasionally instead of a complete absorption, the dead fetus may be compressed by the growing brother into a pergament structure, known as fetus papyraceus. If the fetus is absorbed completely, there aren`t any further complications besides the first trimester bleeding.

If the even appears during the second or third trimester, the severe complications may include:

  • Premature labor.
  • Infection by fetal elimination.
  • Bleeding.

Even at the end of pregnancy, a fetus papyraceus can block the cervix and make necessary a C-section.

The vanishing twin can die due to:

  • A placenta poorly implanted.
  • An abnormality which may determine a major organ failure or their complete lack to the fetus.
  • A chromosomal abnormality incompatible with life.

Frequently, the twin is an empty egg which never develops beyond the early stages of embryogenesis.

The frequency of the syndrome is of 1 to 8 pregnancies, and may remain unknown in many cases. The phenomenon appears frequently in pregnancies created as a result of IVF. Ultrasound scans are performed early in these pregnancies, so if the multiple conception took place, it can be noticed more than one amniotic sac in the first few weeks and after a period of time the brothers will disappear.

Why this Syndrome Occurs?

The causes of this syndrome are often unknown. The abnormalities that result from the disappearance of a twin seem to be present from early pregnancy, and not develop along the way.

The analysis of the placenta or fetal tissue often shows chromosomal malformations, while the surviving twin is generally normal. An improper implantation of the umbilical cord might be a cause as well.

Mechanisms of the Viable Twin`s Complications

Cerebral Palsy

Researchers have proposed that vanishing twin syndrome may determine spastic cerebral palsy at the viable brother. A possible mechanism is the transfusion of thromboplastin proteins from the death brother at the viable one, leading to disseminated intravascular coagulation (DIC). Supposedly, DIC results from reversing the blood flow from the death brother to the viable one, carrying the thromboplastin proteins in circulation. This high load with thromboplastin proteins is considered as leading to a status of DIC in viable fetus with damage in the central nervous system.

Another proposed theory is the effect of the high amount of blood lost by the viable fetus against the low vascular resistance system of the death fetus through the placental anastomoses. This transfusion may determine large fluctuations in the intravascular pressures leading to intravascular hemorrhage and cerebral palsy.

Aplasia Cutis

The developing mechanism of aplasia cutis is vascular, with a decreased perfusion in the affected area by the death of the brother.

Signs & Symptoms

Most of the times, this syndrome is asymptomatic, meaning that the expecting mother doesn`t realize that one of her fetuses disappears until she visit the doctor`s office at the regular examination she has to make. However, there are cases where pregnant women might show the signs of a miscarriage and might experience, like:

  • Pelvic pain.
  • Abdominal cramps.
  • Vaginal bleeding.

Decreased hormonal levels in the body due to various blood tests may show the fact that one of the fetuses has been aborted.

First Trimester

Morbidity varies in the appearance of the phenomenon during the first trimester. It`s usually limited. The mother is prone to the development of vaginal bleeding and cramps. If the event occurs late, morbidity can be similar to the one from the second or third trimester.

Second & Third Trimester

Maternal complications include:

  • Premature labor.
  • Infection through retained fetus.
  • Severe puerperal hemorrhage.
  • Consumptive coagulopathy and obstruction of birth canal by a fetus papyraceus, which cause dystocia and requires C-section.

Evolution of the Disease

Synchronization of this event affects the prognosis of the viable twin and maternal complications. If the event appears in the second half of pregnancy:

  • The fetus may develop cerebral palsy or apalsia cutis.
  • The mother may develop premature birth, infections, hemorrhage puerparel, consumptive coagulopathy or birth blocking.

Diagnosis

Before using ultrasounds, the diagnosis of this syndrome was given by examining the placenta after birth. At present, the presence of multiple fetuses is detected during the first trimester of pregnancy. A subsequent ultrasound may reveal the disappearance of one of the babies.

For example, a woman can perform an ultrasound in the 6th or 7th week of pregnancy. The doctor identifies 2 fetuses, and tells the woman she`s going to have twins. When she returns to the doctor`s office in a future visit, the doctor only notices the heart beats of a single fetus. Another ultrasound is performed, therefore being noticed the existence of a single fetus.

Sometimes, a woman might experience signs that show the loss of a pregnancy, and the ultrasound shows the presence of one single baby inside the uterus.

This syndrome has been diagnosed lots of times since ultrasounds have started to be used. A frequency estimate shows that this condition occurs in 21% to 30% of the multifetal pregnancies.

Lab Studies

  • The recent phenomenon causes the increase of plasma protein A associated with the pregnancy and free beta-HCG.
  • Alpha-fetoprotein is increased compared with a normal pregnancy.
  • Human chorionic gonadotropin growth rate is lower than in a normal pregnancy.

Imaging Studies

Ultrasound is used to confirm the diagnosis of early twin pregnancy. Monitoring the placenta through ultrasound shows the loss of a fetus in the pregnancy evolution.

Amniocentesis after the diagnosis of a vanishing twin by ultrasound detects XY cells by FISH and PCR.

Chorionic villi sampling is useful if the placenta has a mosaic pattern, but at birth there`s only one result.

Differential Diagnosis

  • Miscarriage.
  • Deciduous reaction on ultrasound.
  • Amniotic cavity observed on ultrasound as a second fetus.
  • Chorionic sac considered the second fetus.
  • Extraembryonic coelom seen as the second fetus.
  • Subchorionic bleeding or hydropic villi change of considered the second fetus.

Can Twins Survive if One Dies?

The death of any of the fetuses in a multiple pregnancy will always be a sad and sometimes unexpected event. But frequently, the surviving fetus`s health isn`t affected and everything will then lead to a healthy delivery. This is specifically true when things happen early in the pregnancy, but it`s also true even when a co-twin`s death occurs after the first trimester of pregnancy.

Among the most essential factors in such cases is whether or not the twins share one single placenta or amniotic sac.

Twins in separate sacs and with separate placentas are considered the most frequent twin types. This happens in around 75% of all twins. Generally speaking, this type of twins has the lowest risks of any complications during pregnancy.

If it may happen for the twins to share the amniotic sac (this occurs in less than 1% of cases), their umbilical cord might become tangled. This may block the flow of blood through one or even both umbilical cords.

Twins which share the same placenta may have connection between their own circulations. In such a situation, the death of one of the fetuses may affect the flow of blood for the other fetus.

At birth, the dead twin`s tissue might be visible, although the more time passes between the death and the birth, the harder it might be to identify. If there`s some time passed, the fetal tissue might become flattened against the placenta of the surviving twin, this being known as fetus papyraceous.

Treatment & Prognosis

If a papyraceus fetus is residual, the pregnancy needs to be monitored carefully by series of ultrasounds for evaluating the viable fetus. The risks are:

This fetus is at risk of low birth weight and gestational age. Uncomplicated vanishing twin syndrome doesn`t require special medical therapy.

In addition, the loss of a twin brother, the fetus which survives shows an increased risk of cerebral palsy, especially if the syndrome occurs in the second half of pregnancy. Other forms of morbidity reported to the surviving fetus are aplasia cutis or areas of skin necrosis. At brothers connected by placental vascularization, transient hypotension at the viable fetus at the time of death leads to poor perfusion and skin necrosis.

Image courtesy of medcaretips.com

Show Comments

358 Comments

  1. xmc.pl May 7, 2022
    • Gyngeassy May 18, 2023
    • embarry June 23, 2023
    • FPwUophzr July 29, 2023
    • UhDZLdHq September 3, 2023
  2. www.xmc.pl May 9, 2022
  3. RalphLep June 5, 2022
  4. ChesterDyesy June 7, 2022
  5. IverDarm June 7, 2022
  6. Stromvar June 7, 2022
    • Higuilk April 23, 2023
    • Rublips May 29, 2023
    • Rublips June 6, 2023
    • sbWplue July 4, 2023
  7. Rcmpdc June 27, 2022
  8. incuchrib August 20, 2022
  9. Exceest September 1, 2022
  10. cialis online September 1, 2022
  11. Clalsekew September 1, 2022
    • Iodindila May 9, 2023
    • LdgOScv July 25, 2023
    • Fodgiggip January 15, 2024
  12. Juibrerit September 3, 2022
    • Gyngeassy May 16, 2023
    • embarry June 22, 2023
    • lBYvJT July 27, 2023
    • GDZXXHd September 1, 2023
  13. Chooggued September 3, 2022
  14. Groonract September 5, 2022
    • Emikify March 5, 2023
    • Ethigue April 30, 2023
    • embarry June 1, 2023
    • wUDGyE July 13, 2023
    • EggflwDo August 15, 2023
  15. Duemill September 5, 2022
  16. aftelve September 7, 2022
    • Peeguic May 25, 2023
    • Rublips June 24, 2023
    • oZQBJT August 14, 2023
  17. zesserb September 7, 2022
    • Higuilk April 23, 2023
    • Rublips June 6, 2023
    • BdPBglawU July 4, 2023
  18. Joydrok September 10, 2022
  19. plalePasy September 10, 2022
  20. Fralief September 13, 2022
    • Iodindila May 17, 2023
    • Rublips June 17, 2023
    • CaTtMGK August 4, 2023
    • tDRQzqphq December 17, 2023
  21. Kneense September 13, 2022
  22. Scuctut September 17, 2022
    • Iodindila May 5, 2023
    • ElYLcF July 20, 2023
  23. Ignonumma September 17, 2022
    • UncomeRem February 22, 2023
    • cloravy April 22, 2023
    • gissuri May 25, 2023
    • mPlhuY July 3, 2023
    • piomync January 13, 2024
    • Higuilk April 29, 2023
    • Rublips June 3, 2023
    • OkEBHF July 13, 2023
    • Vejoift November 26, 2023
  24. Rhywoto October 7, 2022
    • UncomeRem February 23, 2023
    • cloravy April 23, 2023
    • gissuri May 26, 2023
    • gissuri June 7, 2023
    • qSHxEV July 4, 2023
    • Vejoift October 28, 2023
  25. browse this site October 7, 2022
  26. tuplilt October 8, 2022
  27. spoorge October 13, 2022
  28. neelery October 13, 2022
    • Emikify February 23, 2023
    • Ethigue April 23, 2023
    • embarry June 7, 2023
    • uDEAzndxf July 4, 2023
    • unWiheIKm August 7, 2023
    • Vejoift December 16, 2023
    • Emikify March 12, 2023
    • Gyngeassy May 7, 2023
    • pQNXyPsKf July 19, 2023
    • ILhpEDDX August 21, 2023
    • vaqYUMy January 3, 2024
  29. driency November 8, 2022
    • UncomeRem February 20, 2023
    • UncomeRem February 21, 2023
    • cloravy April 21, 2023
    • gissuri May 24, 2023
    • gissuri June 5, 2023
    • MpiDbA July 1, 2023
  30. Edittef November 11, 2022
    • Emikify March 18, 2023
    • Gyngeassy May 10, 2023
    • embarry June 17, 2023
    • cJOZLNf July 23, 2023
    • ioBNIZRUl August 25, 2023
    • GEJqHm October 30, 2023
  31. Asseptors November 14, 2022
  32. roarrop November 15, 2022
  33. Bifaple November 18, 2022
  34. deelvinia November 23, 2022
    • Iodindila May 13, 2023
    • nxEbUntrd July 29, 2023
  35. Encmua November 28, 2022
    • Emikify March 16, 2023
    • Gyngeassy May 9, 2023
    • rDuKEkN July 22, 2023
    • DgfKaLoC August 24, 2023
  36. Edgetdype December 11, 2022
  37. Bonsirl December 11, 2022
  38. Adopity December 11, 2022
  39. Equillalk December 13, 2022
  40. blivybiab December 16, 2022
  41. Davidopera January 22, 2023
  42. ETHIPMENE January 23, 2023
  43. Tagsamida January 23, 2023
  44. Beulah Cyril January 24, 2023
  45. Gypereaph January 25, 2023
  46. Cresteriz January 25, 2023
  47. Engague January 26, 2023
  48. Cresteriz January 27, 2023
  49. Fafeseesk January 28, 2023
  50. ErrodaY January 29, 2023
  51. Cresteriz January 31, 2023
  52. Cresteriz February 3, 2023
  53. jepledo February 3, 2023
  54. Yztdqb February 5, 2023
  55. gakeldera February 7, 2023
  56. ETHIPMENE February 8, 2023
  57. tam compact February 10, 2023
  58. Dangext February 15, 2023
  59. Pagiahhom February 17, 2023
  60. suilk February 17, 2023
  61. insubylib February 18, 2023
  62. nercisa February 19, 2023
  63. 토토검증사이트 February 20, 2023
  64. fefevenly February 26, 2023
  65. itemync March 8, 2023
  66. Emikify March 21, 2023
  67. Call Girls Barwani March 30, 2023
  68. son dakika haberleri March 31, 2023
  69. NathanImara April 9, 2023
  70. ErnestVialf April 9, 2023
  71. HectorReeft April 9, 2023
  72. ScottSoync April 10, 2023
  73. vaf April 25, 2023
  74. alex been April 29, 2023
  75. sor May 1, 2023
  76. Den May 3, 2023
  77. Iodindila May 12, 2023
  78. Gyngeassy May 13, 2023
  79. online games May 16, 2023
  80. Mic May 18, 2023
  81. jaste June 15, 2023
  82. embarry June 19, 2023
  83. penis enlargement June 24, 2023
  84. bezogoroda.ru July 4, 2023
  85. fef July 5, 2023
  86. ivistroy.ru July 6, 2023
  87. Huh July 10, 2023
  88. Vejoift July 19, 2023
  89. GET July 19, 2023
  90. sXuzwO July 25, 2023
  91. jxiryeM July 28, 2023
  92. HectorReeft August 4, 2023
  93. ErnastVialf August 6, 2023
  94. Dereknon August 7, 2023
  95. Jimmykaply August 8, 2023
  96. Bella Annunziata August 26, 2023
  97. Philomena Matheny August 28, 2023
  98. ANIMxGFkM August 29, 2023
  99. RNS-MO-But September 2, 2023
  100. weamn September 6, 2023
  101. scholding September 13, 2023
  102. tof October 8, 2023
  103. Fast_Build_S October 11, 2023
  104. Fast_Build_P October 13, 2023
  105. 안전놀이터 November 20, 2023
  106. 사설토토 추천 November 20, 2023
  107. cWgrrPeVW November 26, 2023
  108. fun88 December 9, 2023
  109. Movies December 13, 2023
  110. สล็อต777 December 17, 2023
  111. slot pg 54 December 17, 2023
  112. N-Dom_Kek December 17, 2023
  113. N-Dom_Kek December 27, 2023
  114. ppu-prof_Oa January 7, 2024
  115. link rgo303 January 11, 2024
  116. shape caps January 31, 2024
  117. crystallon.top February 9, 2024
  118. najlepszy sklep February 13, 2024
  119. e-commerce February 15, 2024
  120. ecommerce February 16, 2024
  121. sklep online February 17, 2024
  122. Syhkheive February 23, 2024
  123. CnntArrek February 28, 2024
  124. najlepszy sklep internetowy February 28, 2024
  125. najlepszy sklep March 2, 2024
  126. Xtnvadelt March 4, 2024
  127. ppu-prof_Oa March 9, 2024
  128. jak March 20, 2024
  129. Charlesgigma March 30, 2024
  130. ppu-pro_Fus April 3, 2024
  131. jungle beast pro results April 18, 2024
  132. Nannie79 April 19, 2024
  133. Floydaname April 20, 2024
  134. WilliamHof April 21, 2024
  135. PedroDet April 23, 2024
  136. Seo-Ul-rox April 24, 2024
  137. ZccrPLUPS April 29, 2024
  138. Bcedadelt April 29, 2024

Leave a Reply