Vanishing Twin Syndrome

Jenna and Ted were over the moon when Jenna's first ultrasound showed that she was carrying twins. They couldn't thank God enough for giving them the joy of two babies after years of trying to start a family. However, Jenna's ultrasound during the thirteenth week of pregnancy showed just one baby! Where did their other baby go?

What Jenna and Ted witnessed is the vanishing twin syndrome in which one of the twins dies early in pregnancy (usually within the first trimester) and is absorbed by the placenta, surviving twin and the mother herself. All this usually happens without the knowledge of the mother or the mother may experience a light bleeding, but continues with the pregnancy of the surviving fetus.

Causes

Even if one of the twins is lost early, it definitely is a loss that is difficult to cope with. Some mothers may have a feeling that it was probably the wrong side that they slept on or some wrong thing that they ate that may have caused the loss of one of the twins. However, it is important for all such mothers to know that the baby was lost due to a chromosomal abnormality. The genetic problem in the embryo prevented it from developing into a fetus. Improper placental implantation or some developmental fault that may hinder the development of the major organs could cause the death of the 'vanishing' twin.

Symptoms

In many cases a mother experiencing this syndrome may not have any apparent symptoms. However, she might experience some miscarriage symptoms like vaginal bleeding, cramping and pelvic discomfort. Also the hCG levels in the first trimester are declining in such cases, when they are expected to rise in twin pregnancies. This may be a reason, although direct relation between vanishing twin syndrome and hCG levels haven't been conclusively established. However, the bleeding is not as heavy as it is in case of a miscarriage. It is so because the other twin is still there in the womb keeping the hormone levels high so that the placental lining is not shed. However, there is a small chance that the other baby may also be lost. If this happens, the mother will realize through heavy bleeding and would be the case of an early miscarriage.

Complications

If the twin is lost in the first trimester there is no threat to the health of the mother or the surviving fetus. The pregnancy continues normally and there are no clinical symptoms, either in the mother or the other twin. However, if the (vanishing) twin dies in the second or the third trimester there are chances that the surviving fetus may suffer from cerebral palsy.

There is a possibility of the premature labor, infection due to the death of the other twin and hemorrhage. In fact in such a case there is a threat to the continuation of the pregnancy itself. Although in most cases the vanishing twin is absorbed by its twin, the placenta or the mother's body, sometimes the dead fetus may be compressed by the surviving twin. As a result it may change into a flattened parchment like mass known as the fetus papyraceus. This fetus papyraceus may block the cervix during delivery that might require a cesarean delivery for the surviving twin.

How Common is Vanishing Twin Syndrome

The first instance of this twin syndrome was reported as recently as in 1945. Since then this phenomenon seems to be on a rise. However, as more and more studies are being done into the syndrome, it is being realized that this is not a recent occurring. Research indicates that almost 1 out of 8 births started as a twin pregnancy. However, neither the mother nor the doctors ever had the knowledge of the existence of one of the other twin. This is because in case of the vanishing twin syndrome, one of the twins is lost early in pregnancy.

With the increase in the availability of ultrasound in early stages of pregnancy, cases of twin pregnancies are easily reported nowadays. In case one of the embryos is lost due to the condition, then this loss is detected and reported in the subsequent ultrasounds. This explains the increased incidence of the phenomenon of the vanishing twin syndrome in recent times.

Though the condition is believed to have been around for long, it has come to light only recently. The loss of one of the fetus is difficult for any parent to cope with. However, it is important to understand that it is nature's way, by which it eliminates a life with chromosomal defect. This is for the benefit of all; as had the fetus with chromosomal abnormality survived it would have caused greater trauma both to the baby and its parents as till date there is no cure for genetic disorders.