$Unique_ID{PAR00442} $Pretitle{} $Title{Pregnancy: The Third Trimester: Special Situations} $Subtitle{} $Author{ Editors of Consumer Guide Ellis, Jeffrey W Ellis, Maria} $Subject{Third Trimester Special Situations multiple births Twins triplets quadruplets older pregnancy pregnancies fertility drugs identical fraternal ultrasound Two babies amniotic sacs placentas abdomen stretching sooner aches earlier Backache leg pain pains Stretch marks Fatigue placentas Complication Complications premature delivery preemies Anemia iron deficiency preeclampsia} $Log{ Fraternal and Identical Twins (Caption)*0044201.tif Fraternal Twins (Image)*0044201a.tif Identical Twins (Image)*0044201b.tif} Miracle of Birth The Third Trimester: Special Situations Carrying More Than One Baby We all share a common fascination with multiple births. Twins, triplets, and quadruplets excite the curiosity of family, friends, and the news media alike. As their due date draws near, many women groan that they must be carrying more than one baby. In some cases, they are right. Incidence Twins are actually relatively common; they occur once in about every 88 deliveries. Triplets (three babies) occur once in about 7700 deliveries; quadruplets (four babies), once in about 680,000 deliveries; and quintuplets (five babies), once in several million deliveries. There are a number of factors that may increase your likelihood of having a multiple birth. The older you are when you become pregnant, the more likely you are to have a multiple birth. Also, the more pregnancies you have had, the more likely you are to carry more than one baby. Your family history is also important. If a woman has twins in her family, she is more likely to have a multiple birth. The use of certain fertility drugs, which can cause the production of two or more eggs at a time, may also lead to a multiple birth. Of course, some women who have none of these predisposing factors experience multiple births. Types of Multiple Birth Babies from a multiple birth are either identical or fraternal. Identical twins, for example, are exact duplicates of each other. They are always the same sex--either two boys or two girls. Identical twins result when a single egg divides into two similar structures shortly after fertilization. Each of these resulting cells grows to become a separate but identical baby. About one third of all twins are identical. Fraternal twins, on the other hand, develop from two different fertilized eggs and may or may not be the same sex. Even though fraternal twins share certain family traits and characteristics, they will not be identical in appearance. About two thirds of all twins are fraternal. Higher numbers of babies--triplets or quadruplets, for example--may be identical, fraternal, or a combination of the two. In the case of triplets, for example, two babies may be identical and one fraternal. With quadruplets, two babies may be identical and two fraternal. How Will I Know if I'm Carrying More Than One? During your pregnancy, your doctor may suspect that you are carrying more than one baby based on several observations. First, your doctor may notice that your uterus is growing quite rapidly, more so than he would expect for one baby. If, for example, your uterus is twice as large as it should normally be during your fourth month, your doctor may suspect twins. Another tip-off that you may be carrying twins is that you gain weight rapidly after the fifth month of pregnancy. Also, during your monthly office visits, your doctor may be able to feel two distinct heads or hear two heartbeats; each is a sure sign that you are carrying more than one baby. An ultrasound test (see The Fourth Month: Ask the Doctor) can also be used to diagnose the presence of more than one baby. This safe procedure uses sound waves to create a picture of the baby--or babies--within your uterus. If your doctor sees two separate babies, then you are definitely going to have twins. Before the widespread availability of ultrasound tests, X rays were used to detect the presence of more than one baby. Today, however, the potential side effects of X rays make ultrasound the test of choice for determining if you are carrying more than one baby. Early diagnosis is important in order to provide you and your babies with appropriate prenatal care. If you are carrying more than one baby, your doctor will need to conduct further tests and will need to see you much more frequently. What to Expect if You are Carrying More Than One Baby As you might imagine, being pregnant with two or more babies differs from being pregnant with just one. Two babies and two amniotic sacs (and, in some cases, two placentas) mean twice as much weight to carry and twice as much stretching of your abdomen. Therefore, many of the usual aches and pains of pregnancy will occur sooner and may be more extreme. Backache and leg pain will occur earlier and will probably be more intense because your uterus will expand more rapidly and will grow larger than it would if you were carrying only one baby. Stretch marks on the skin of the abdomen will also appear sooner and may be larger. Fatigue may also be more intense. Since two placentas may now be producing hormones, morning sickness may be more intense and may last beyond the first trimester. With more than two babies, these aches and pains are accentuated even more. Complications Unfortunately, carrying more than one baby is also associated with a slightly higher risk of certain complications. The most serious complication is the premature delivery of the babies--that is, delivery well before your estimated due date. It is not entirely understood why nearly two thirds of all women who are carrying twins go into labor before the ninth month. Labor may occur even earlier with three or more babies. Some authorities believe that the mother's body may be fooled into thinking it is time to go into labor. Once the uterus reaches a certain size--whether it contains one, two, or three babies--it may begin to contract, and labor may start. The problem with premature babies ("preemies") is that their organs, especially the lungs, may not be developed enough for them to live outside the mother's body. These premature babies generally require expert medical care in intensive-care nurseries. The woman who is carrying more than one baby is also more likely to develop certain complications. Anemia--an abnormally low blood count--is one common complication. In pregnancy, the developing baby normally takes iron from the mother's body to make blood cells and tissue, so the mother may become iron deficient and develop a low blood count. Two or more developing babies take more iron and therefore increase the mother's likelihood of developing anemia. Another common complication in the woman who is carrying more than one baby is preeclampsia, a condition marked by extremely high blood pressure (see The Second Trimester: Special Situations). If you are pregnant with more than one baby, your doctor will examine you more frequently and will give you specific instructions about nutrition and physical activity. In general, you will be advised to stop working and reduce your physical activity after your thirtieth week of pregnancy. Your doctor will probably also increase your iron supplement to prevent anemia. With early diagnosis and good prenatal care, most of the increased risk associated with carrying more than one baby can be reduced or eliminated.