What Is Vanishing Twin Syndrome? Causes, Symptoms And Treatment

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Vanishing twin syndrome is a loss or miscarrying of one of the twins or multiples. As a result, one of the embryos disappears or is absorbed partially or completely by the twin, multiple, placenta, or the mother. The first case was documented in 1945. Research states that the likelihood of vanishing twin syndrome is 36% for twin pregnancies and half for multiple pregnancies (1) (2).

However, most of this syndrome’s symptoms are similar to normal miscarriage symptoms, with some exceptions. Early ultrasounds in the first trimester and follow-up ultrasound could help manage the condition to prevent maternal morbidities. Read on this post to know about the causes, symptoms, complications, diagnosis, and treatment of vanishing syndrome.

In this post, learn about vanishing twin syndrome, including its causes, symptoms, and treatments.

What Causes Vanishing Twin Syndrome?

Although the cause behind vanishing twin syndrome is not well understood, certain prospective studies found the probable causes of miscarriage. These include (2):

  • Around 20-30% of pregnancies with assisted reproductive techniques (ART). This may occur as several embryos are introduced into the uterus, raising the possibility of twin or multiple pregnancies.
  • Advanced maternal age, especially after 30 years.
  • Pregnancies achieved with ART in advanced maternal age may increase the risk for chromosomal abnormalities in the fetus. This may lead to a miscarriage in twin pregnancies with a chromosomal abnormality in one of the twins.
  • Any structural abnormality of the placenta can also threaten the fetus.
  • Genetic factors that are likely to cause congenital abnormalities

What Are The Symptoms Of Vanishing Twin Syndrome?

The common manifestations of a vanishing twin syndrome include (2):

  • Abdominal or uterine cramps
  • Pelvic pain
  • Vaginal bleeding or spotting
  • Slower rise of human chorionic gonadotropin (hCG)

What Are The Effects Of Vanishing Twin Syndrome On The Mother?

Twin pregnancies with vanishing twin syndrome that occur towards the second and third trimesters can cause severe side effects in the mother, such as follows (2) (3):

  • Gestational diabetes.
  • Early contraction or induced labor leading to preterm birth.
  • Reduction in the required levels of amniotic fluid.
  • Fetus papyraceous, flattening of the deceased fetus can cause hindrance in the normal delivery by stretching the labor duration.

What Are The Effects Of Vanishing Syndrome On The Surviving Twin?

Prospective cohort studies show that vanishing twin syndrome towards the second and third trimesters can lead to neonatal complications and increase the surviving twin’s risk of birth defects. These can include (2):

  • Lower birth weight.
  • Intrauterine growth retardation (IUGR), where the baby’s development inside the womb is affected.
  • Congenital abnormalities due to the flattened demised twin.

Vanishing twin syndrome has also been linked to cerebral palsy in the surviving twin in the case of twin pregnancies (1). The renowned cerebral palsy researcher, Dr. Peter Pharoah’s observation, states that twin pregnancies with vanishing twin syndrome, towards the later weeks of gestation, can raise the risk of cerebral palsy in the surviving twin by 14 times than in normal twin pregnancies (4).

What Are The Diagnosis And Treatment For Vanishing Twin Syndrome?

Vanishing twin syndrome mostly occurs during the first trimester and is generally detected through ultrasound in the early weeks of gestation. Upon detection of a demised twin, an examination of the placenta after delivery can be carried out for the structural details of the vanished twin (1) (2).

Vanishing twin syndrome in the first trimester of pregnancy requires no medical treatment as it does not pose any threat to the mother and the baby’s health. However, twin pregnancies that result in vanishing twin syndrome during the second and third trimesters involve constant medical care to help prevent serious maternal complications and the risk of birth defects (2).

How To Cope With Vanishing Twin Syndrome?

The loss of a twin can be a painful experience. You may feel overwhelmed with mixed emotions of grievance for the deceased twin, along with a sense of comfort and happiness for the surviving one.

Allow yourself to mourn the loss and understand it is normal for you to feel this way. You may also try to focus on the brighter side by taking good care of yourself for the better health of the surviving twin. Surround yourself with your loved ones and do not miss doctor’s appointments to monitor your physical and mental health regularly.

Vanishing twin syndrome is a common form of miscarriage than it is perceived to be. With the imaging modality of ultrasonographic examination, its early detection and treatment are possible. While the loss of a baby can be unbearable and mourning, you can celebrate the gift of life you receive in your surviving twin.


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Aneesha Amonz

Aneesha holds a Bachelor's degree in Biotechnology from USTM, Meghalaya and Master’s degree in Applied Microbiology from VIT, Vellore. She has worked on different research projects in the field of Food Sciences. In addition, she has an internship experience in Oil India Limited as an R&D project trainee. As a writer at MomJunction, Aneesha ensures her content is engaging and... more