Vanishing Twin Phenomenon An interesting phenomenon has been noticed now that ultrasound exams are available for most pregnancies, facilitating detection of pregnancy at earlier and earlier stages. There have been many cases in which early-pregnancy ultrasound exams showed twins, only to have a subsequent ultrasound show only one fetus, with no sign of the other having been present. Sometimes the mother had experienced mild girl thingyl bleeding or cramps, and at other times she had no symptoms. This is the vanishing twin phenomenon. Charles E. Boklage, M.D., and others have studied the vanishing twin, and it has been found to be more common than first realized. In one study, 325 twin pregnancies were identified very early by ultrasound exam and followed through the entire pregnancy. The study reported that 61 (18.8 percent) ended as twin births, 125 (38.5 percent) ended as singleton births, and 139 (42.8 percent) ended as a complete loss of the pregnancy. Generally, the vanishing twin fetus is absorbed back into the uterus or degenerates as pregnancy advances. The likelihood of survival for the other co-twin is good. There may be more twins than we realize. Boklage has concluded that the "true" twinning rate is closer to one in eight at conception. He feels that for every live-born twin pair, there are at least six singletons that have lost a twin without anyone ever knowing it. Some feel that the survival of just a few more of these twin conceptions could increase the twinning rate remarkably. This could be another explanation of why the rate of twins has recently increased. Anyone may have had an undetected twin in the womb. It is conjectured that since twins are more likely to be left-handed than the normal population, left-handed singletons may be surviving co-twins of a vanishing identical! Original text: http://www.nomotc.org/library/twinning_facts.html Vanishing Twin Syndrome - Answers to frequently asked questions about Vanishing Twins Jan 4 2004 What you need to know about: Vanishing Twin Syndrome In recent years, enhanced use of ultrasound early in pregnancy has increased the frequency of diagnosis of twin pregnancy, and unfortunately, has produced a heightened awareness of the phenomenon of Vanishing Twin Syndrome (VTS). Here are the answers to Frequently Asked Questions about this condition. What is Vanishing Twin Syndrome? Vanishing Twin Syndrome occurs when one of a set of twin fetuses apparently disappears from the womb during pregnancy, usually resulting in a normal singleton pregnancy. What really happens? One of the fetuses in a twin pregnancy spontaneously aborts, usually during the first trimester; the fetal tissue is absorbed by the other twin, the placenta, or the mother, thus giving the appearance that the twin "vanished." How is it diagnosed? Here's a typical scenario: A mother undergoes a routine ultrasound early in her pregnancy, for example at six or seven weeks gestation. Two fetuses are detected. The mother is told she is having twins. When the mother returns to the doctor six weeks later, only one heartbeat can be heard with a Doppler scan. Another ultrasound is performed. Only one fetus is identified. In other cases, a pregnant mother experiences symptoms that would seem to mimic miscarriage; however the single baby in her womb remains unaffected. How often does it happen? Scientists have confirmed that the number of twin conceptions greatly outnumbers the number of actual twin births. Some estimates offer that 1 in 8 people started life as a twin, while in reality only 1 in 70 actually are a twin. In "Having Twins," author Elizabeth Noble claims that 80% of twin pregnancies result in the loss of one or both babies. Other studies predict that Vanishing Twin Syndrome occurs in 21 - 30% of all multiple pregnancies in the United States. It is estimated that Vanishing Twin Syndrome will play a role in 50% of assisted ovulation pregnancies. Why is it happening more frequently? Although it would seem that incidences of Vanishing Twin Syndrome are increasing with alarming frequency, it is simply that the detection of the phenomenon has increased. Advancements in ultrasound technology allow modern doctors (and parents) the exciting opportunity to peek into the womb. As more doctors routinely use ultrasound in the first trimester, more multiple pregnancies are identified. And a certain percentage of those will be affected by Vanishing Twin Syndrome. In the past, many women experienced VTS without ever knowing it. What causes it? Just as there is no clear attributable cause for most miscarriages, there aren't always reasons or explanations for the loss of a fetus in a multiple pregnancy. In some cases, the fetus is inviable due to chromosomal or placental abnormalities. Some studies suggest that because these abnormalities are more common in older women, Vanishing Twin Syndrome occurs more often in mothers of advanced age. Vanishing Twin Syndrome occurs with equal frequency in monozygotic and dizygotic twins, although the complications of sharing a placenta between monochorionic monozygotic twins may contribute to the condition. What are the symptoms? There might not be any symptoms. However, some mothers experience some mild cramping, bleeding or pelvic discomfort, similar to miscarriage. Decreasing hormone levels may also indicate that one fetus has been resorbed. What is the treatment? Generally, neither the mother nor the remaining fetus will require any kind of medical treatment. When VTS occurs in the first trimester, the mother usually goes on to experience a normal pregnancy and delivers a healthy singleton. However, in situations where a fetus dies in the second or third trimester, the mother may experience pre-term labor, infection or hemorrhaging. In those cases, doctors will prescribe treatment appropriate for those conditions. What are the ramifications for the mother? Physically, none. But emotionally, the mother may be feeling an awkward combination of grief over the loss of one baby and relief for the viability of the surviving baby. It is important for the parents to grieve in a way that feels appropriate, acknowledging the loss of a child as well as the loss of their identity as parents of multiples. What are the ramifications for the surviving twin? In most cases of first trimester Vanishing Twin Syndrome, there is no physical impact on the surviving twin. A healthy womb experience followed by a normal delivery should be expected. A late pregnancy occurrence of VTS does have some implications for the surviving fetus, just as for the mother. Occasionally, remnants of the resorbed fetus are found in the survivor, in the form of a tertoma tumor containing bone, hair, teeth or tissue fragments. Researchers have found that after 20 weeks, the surviving fetus has an increased risk of cerebral palsy. And asynchronous death may also be a risk if the twins are monozygous and sharing a vascular connection. There is a great deal of speculation about the psychological and emotional impact of Vanishing Twin Syndrome. Some survivors report feelings of longing, guilt, or grief or problems with relationships or sexuality. What happens when the twin doesn't really vanish? Sometimes, remnants of the inviable fetus are found in the mother, placenta or surviving twin. This is most likely to occur during the second or third trimester. Although usually the fetus will be partially resorbed and retained, the death of one twin at around 15 - 20 weeks may result in a fetus papyraceous, a tiny paper-like, flattened fetal remnant. A tertoma tumor containing bone, hair, teeth or tissue fragments is also an indication of a Vanishing Twin. Where can we go for help? Families who have experienced Vanishing Twin Syndrome may need support and encouragement in dealing with their unique loss. Here are some organizations that can provide assistance. Resources for Loss of a Multiple Twinless Twins Support Group Twinless Twins International P.O. Box 980481 Ypsilanti, MI 48198-0481 (888) 205-8962 Center for Loss in Multiple Birth CLIMB, Inc. c/o Jean Kollantai P.O. Box 91377 Anchorage, AK 99509 (907) 222-5321 newsletter@climb-support.org Neuro-Emotional Technique (NET) has been used to help survivors of a vanishing twin and other emotional traumas. NetMindBody.com Dr, Scott Walker NET Incorporated 510 Second Street Encinitas, CA 92024 Original text: http://multiples.about.com/cs/medicalissues/a/vanishingtwin.htm