Many women have an inkling that they are pregnant with twins before it’s confirmed by the obstetrician. Call it a mother’s sense or high levels of hormones, but being pregnant with twins can be a little more challenging and exciting than a regular pregnancy.
Many expectant mothers are curious about how best to prepare, what pregnancy vitamins and multiple pregnancy nutrition. This article highlights types of twin pregnancies, symptoms of twin pregnancies, prenatal care of the twins and any possible complications.
Types of twin pregnancies
There are several different types of twin pregnancies. Conceiving twins can be the natural result of a genetic predisposition, an accident of cell division, or it can be the result of fertilization treatments. The classification is based on how the fertilization that led to the formation of twins occurred.
- Fraternal twins: Also known as ‘non-identical twins’. This is the most common type. During conception two different eggs from the mother are each fertilized in the womb by two different sperm cells from the father. The two eggs form two zygotes, and these twins are therefore also known as ‘dizygotic’ as well as ‘biovular’ twins. This type of twin is more common if there is a family history of twins, also more common for older mothers, with twinning rates doubling in mothers over the age of 35. They are also more likely to occur if fertility drugs are used to help you become pregnant.
- Identical twins: In the formation of identical twins one egg from the mother is fertilized by one sperm from the father. After the embryo is formed it splits and two fetuses are formed. This happens at the very early stages of development. Spontaneous division of the zygote into two embryos is not considered to be a hereditary trait, but rather a spontaneous or random event.
- Conjoined twins: Conjoined twins formation is similar to that of identical twins. However, the zygote divides extremely late, and doesn’t totally split. They are also popularly known as Siamese twins. Apart from sharing placentas and membranes, conjoined twins also can also share body parts and organs. Separation of conjoined twins is the preferred form of treatment, unless it will threaten the lives of one or both babies.
- Semi identical twins: The ‘semi-identical’ twins are the result of two sperm cells fusing with a single egg, before becoming two embryos. This is extremely rare – in March 2007, the journal Nature identified the world’s first case of semi-identical twins who had survived. Even the chances of a single fetus surviving in this way is rare. Most of the time such a conception would go undetected, as the single surviving fetus would appear normal at birth. However the mix of genetic material may surface if the two eggs have different genetic genders and the baby ends up with a mix of male and female gonads, or if it is picked up on a genetic test that’s done for other reasons.
When you are pregnant with twins the levels of hCG will be high. Human chorionic gonadotropin (hCG) is a pregnancy hormone that helps to form the placenta and nourish the embryo(s). The hormone hCG can be detected as early as 11 days after becoming pregnant via a blood test.
With multiple pregnancies, you can expect more of everything. With higher levels of pregnancy hormones, you may feel extreme pregnancy nausea, vomiting, dizziness, constipation, diarrhea, pregnancy mask, and edema. Extreme fatigue is also more common during a twin pregnancy. If you are expecting twins, your body is working twice as hard to nurture and grow two babies. So make sure you eat enough, eat healthily, and take naps.
Many women feel they might have twins because they can feel constant movement in all directions – some report that it feels like they have an octopus inside of them. Or they may find they are expanding very quickly. An ultrasound is by far the most conclusive way to really know if twins are on the way. A twin’s ultrasound can reveal multiples as early as 6 weeks gestation. If you have a hunch or have any symptoms as above, all will be discovered at your first ultrasound scan.
Most of what you read on pregnancy will also apply if you have multiples. However, there are some differences with prenatal care –a twin-carrying mother will be seen more often and will be offered more testing. Twins or multiples puts the pregnancy in the high risk camp, so regular ultrasounds will check for any complication and to make sure that both babies are growing normally. A pregnancy complication called fetal growth restriction is where one or both twins aren’t growing as the optimal rate, and so pregnancy growth rates must be monitored. You may also be offered DNA testing to find out if they are fraternal or identical.
When expecting twins, you may need to increase the amount of certain vitamins and minerals in your pregnancy diet in order to satisfy the needs of your babies. Your health care provider will probably recommend that you increase your intake of folic acid and iron in order to prevent neural tube defects and anemia. The American College of Obstetricians and Gynaecologists recommend an extra 300 calories per day per baby, or an extra 600 calories daily if you are expecting twins. You only need to take one pregnancy multivitamin, but make sure that it has 400 micrograms of folic acid. Anemia can be a problem with multiples, however, it is easier to increase your daily dose with iron rich foods as iron supplements can cause constipation. Water consumption is also essential with multiple pregnancies. Try to drink at least eight glasses of water a day.
If you are expecting twins, it is generally suggested that you gain between 35 and 45 pounds over nine months, with the bulk of this weight gain occurring in the second and third trimesters. Be sure to speak with your health care provider about what a safe and healthy weight gain would be for you.
Twin pregnancies are associated with more pregnancy complications.Carrying twins does put you in the higher risk category, but don’t worry — most twin pregnancies do result in healthy babies and healthy mothers, too.
- High blood pressure in pregnancy is about three times more common in twin pregnancies than in single pregnancies.
- Anemia is more common, when two babies make greater demands on your supplies of vitamins and iron. Eating healthily is a vital part of caring for yourself and your baby.
- Too much fluid (hydramnios or polyhydramnios) around the baby can also be a problem, and in most cases the exact cause is not identified. This, in turn, can also lead to premature labor.
- Bleeding in late pregnancy, due either to a low-lying or partially detached placenta, is also more common in twin pregnancies.
- Twin-to-twin transfusion syndrome, (TTTS) when one twin shares the other’s blood supply, is a rare but potentially serious complication in identical twins. One baby (the donor) ends up giving blood to the other (the recipient). TTTS can harm the health of both babies, so early detection, by monitoring growth rate, and also laser treatment can help your twins recover from this condition.
Chances of having a miscarriage are higher when you are carrying more than one baby. That’s mostly because the risk of chromosomal abnormalities is higher in a twin pregnancy. As with single pregnancies, the chances of miscarriage are highest in the first 12 weeks.
Vanishing twin syndrome
Another common potential problem in multiple pregnancies is the so-called vanishing twin syndrome, and happens more often than you might think. An ultrasound will detect twins from about six weeks when they are just 3mm long. Two tiny embryos can be seen but, about 21-30 % will subsequently disappear before 12 weeks and only one grows to term. When one of a twin conception fails to survive at this early stage, the lost twin is reabsorbed into the mother’s body or miscarried, which may cause some vaginal bleeding. The remaining twin continues to develop normally.
Twin pregnancies can be one of the most exciting types of pregnancy. However, there are potential issues to be aware of. During the pregnancy, you will have more pregnancy hormones and that likely means more of the symptoms, including morning sickness, constipation, diarrhea, pregnancy mask, edema and weight gain. And you are less likely to go to term. According to the March of Dimes, close to 60 percent of all twins and more than 90 percent of triplets are born prematurely (before 37 weeks). If you are having multiples, make sure to attend all your obstetrician visits; they are vitally important to monitor the babies’ health and growth.