Vanishing Twin: Take it easy

Vanishing twin syndrome is when one of your twin baby just disappears in your womb during the course of pregnancy. It can also represent one or more babies lost in triplet, quadruplet or more.

This syndrome becomes more widely identified with the use of early pregnancy ultrasound scan. It occurs when an early ultrasound scan reveals 2 or more babies but a later scan shows less than that. The loss of fetus (baby in womb) can happen at any point of pregnancy. It can be in the first, second or third trimester. Generally, the earlier it happens, the better the outcome to the viable fetus and mother. Some research reveals that about 10-15% of single baby born are initially twins.

    Fetus papyraceus

 

No one knows exactly what causes vanishing twin syndrome. It is believed that the vanished fetus has some chromosomal or genetic defect and is aborted for good. The viable twin has normal chromosome and usually no other abnormality, but may have increased risk of cerebral palsy if it occurs after the second half of pregnancy. For mother side, there is some risk for complication if it happens later in pregnancy, such as preterm labour, infection of the retained material, post-delivery bleeding, obstruction of labour etc. However, if vanishing twin syndrome occurs in the first trimester (<12 weeks), these complication are very unlikely.

Vanishing twin syndrome may cause some per vagina bleeding and/or lower abdominal discomfort. The vanished fetus can “disappear” completely, form part of the placenta or become “mummified” depends on at what stage it starts to disappear. Mummified fetus need close observation during the pregnancy as it has higher risk to cause complication.

So, don't panic or feel too sad if your doctor tell you that one of your twin just disappears. It is actually good as if the disappeared baby is born, it will give you more problems as it has genetic defect. If the phenomenon occurs in the first half especially first trimester, there should not be too much worry.