Twin pregnancies are the same - a split from the eggs, known as "with the eggs of twins," all about the twins, 1 / 3; from two different eggs develop into twins, said the abuse "of different egg twins ", accounting for about 2 / 3. With eggs is because of a fertilized egg in the early development of embryos split into two, and the formation of twins of different eggs because the mother's ovaries at the same time from two eggs, and fertilization, respectively, into a fetus. Eggs of different genetic twins and family (especially maternally inherited), race (blacks higher), greater age of the mother, a high number of production-related, and with eggs of twins has nothing to do with the above-mentioned factors, is purely an accident phenomenon. Recently, the medical profession in the treatment of infertility, they often use ovulation enhancers, which often emit more than two eggs, so twins, triplets repeatedly heard the case.

Medically think, with the eggs of twins is the real twins, because it must the same gender twins, physical and performance of many genes that have similar characteristics. Different eggs of twins were not really twins think they may be the same gender may also be different, while their physical characteristics are not similar, so different eggs of the relationship between the twins and the general relationship between brothers and sisters is the same as the

In the end is how to identify identical twins or fraternal twins then?

Identification of many ways. First of all, if the twins of different sex, then they are definitely fraternal twins. If the same sex, then also the need for further distinction. At birth, the doctor may tell you that two children is a placenta placenta or two. A placenta that is identical twins, the two are fraternal twins placenta. However, this concept is wrong. Although the placenta, fetal membranes and the status of the eggs of twins have a certain relationship, but not absolute, and therefore should not be judged based solely on this.
Ordinary people will be judged through the looks, and some twins is like a mold carved out like, most of them are identical twins, it does not quite resemble much longer then most of the fraternal twins. This method does have some scientific basis, we call this method for a similar law. However, it is far from enough to rely solely on physical appearance, but also must include a number of other features, such as dermatoglyphics, hair color, hair form and density of iris color and structure, before and after the hair, earwax, ear, nose shape,face type, lips, eyelids, teeth out, whether or not the middle finger hair, skin color and structure, freckles, benzene thiourea (PTC) taste ability of the taste. It appears that this method also is too much trouble.

Similar method can also be achieved through the identification of blood type. General must be a joint determination of several blood types, such as ABO, P, MN, S, Rh, etc., the more blood type determination, the higher the accuracy. And above have a different blood type, compared with fraternal twins. If all the same, you can in a certain level of probability say that they are identical twins.

Now we have another more reliable way to do this is to identify DNA. Its working principle and paternity testing is similar to. General, simultaneous determination of nine loci, identification of the reliability of the results can be achieved more than 99%. Twins only need to provide very little blood, you can complete the identification. This work will complete the forensic center.

The formation of human twins have the following two types ① from a fertilized egg in the blastocyst inner cell is divided into two groups and the development of the fetus into two twins for the same call. This split produced twins have the same genetic characteristics, therefore, of the same sex, personality and looks exactly like. ② At the same time by the two egg fertilization and development of the fetus grew up from two different eggs for twins, the majority of twins (about 75%) is this. Because they are fertilized by two different development, they have different genetic characteristics, character and appearance of similarity is less than the former. The latter twins may be the same sex, or it may be of different gender. Demographic and medical studies have shown that identical twins born in the frequency of relatively stable, inter-regional, inter-ethnic, as well as the different periods of time than the less variable. And fraternal twins born in the frequency of the geographical and ethnic differences in the larger, and in recent years has increased year by year trend. On race, the black race big countries - Nigeria, the frequency of twins can be as high as the number of women giving birth 40 ‰; white race center; home at the end of the Asian ethnic origin.

The selection of identical twins is mainly affected by the family of genetic factors. The emergence of fraternal twins in addition to have familial, but also with women of childbearing age (over 30-year-old woman the opportunity more than 20-year-old women), food, iatrogenic factors. In recent years, for the treatment of infertility, as well as to make childbearing women in pregnancy improve the capacity of commonly used hormones to induce ovulation, the result also increased the frequency of twins was born.

Pregnant with twins, whether it is double female, double male, or "dragon and phoenix" tires, and no matter you are a hi or to worry about during pregnancy should note the following.

1. Nutrition: twin pregnancy on the mother is a great test. In twin pregnancy, the mother and fetus in a pregnant than those with single-birth pregnancy-prone diseases, especially difficult to keep up with nutrition, which calls attention to pregnant women to rest, nutrition, mainly protein, such as the human body necessary for nutrients should be promptly added to reduce future trouble.

2. Make check-up: twin pregnancy at risk of pregnancy-induced hypertension syndrome, manifested as unexplained high blood pressure, edema, proteinuria, severe pre-eclampsia can lead to convulsions, seriously endanger pregnancy (births) women and the baby's life. Women have twins apart from the attention of rest, the daily sleep time should not be less than 10 hours, sleep in the left decubitus appropriate, than to go to the hospital for prenatal examinations for early detection of disease, early treatment.

3. To avoid premature delivery: the fetus as a result of the two have the same elbow in the womb to grow up, will the excessive expansion of the uterus, uterine twins difficult to lengthen to adapt to the degree of growth is too large. Therefore, more common in premature twin pregnancy, especially in pay no attention to the break. Therefore, the attention to rest is the main measures to avoid premature delivery.

4. Anemia prevention and control: In general, pregnant women physiological anemia in the twin pregnancy, when more prominent, mainly iron deficiency, or not enough protein. Iron more animal foods such as liver and other animal offal, vegetables in the cabbage, celery, etc. can eat. But do not eat spinach, because spinach in tannin will hinder the absorption of iron. The past, consider the role of spinach has Buxue is wrong.

5. To prenatal hemorrhage: twin pregnancy are susceptible to placenta previa. This is a painless late pregnancy placenta and endometrium of bleeding caused by stripping. Because it is painless, some pregnant women in the sleep deprived a large number of blood for medical treatment. However, this disease, as it is progressive, first have a small amount of bleeding, to stop a few days after the increase, the last massive hemorrhage. Therefore, history has a small amount of bleeding, pregnant women and their husbands should always pay attention to prevent accidents.

6. Must go to hospital birth: twin pregnancy as a result of the specificity and dangerous, so the requirements to the best maternity hospital to be strict in order to have timely rescue risk, such as the occurrence of dystocia elbow can be a timely cesarean section, have a blood transfusion when bleeding such as ambulance and other equipment and blood banks.

Some people think that if we can artificially cause a multiple birth pregnancy, both easy and which children, not the best of both worlds?

In fact, such ideas is not only undesirable, but will damage women's physical and mental health, mainly because of:

1. Difficult to do so, according to the literature on the twin birth rate of only 1 ‰, 3 births 1 / 5000 ~ 1 / 10000, other multiple birth pregnancy and even less.

2. No way to gain the upper hand: Although there are many factors that can cause twins pregnancy, but its exact cause is not very clear, at present and consider the following factors may be relevant: geographic and ethnic factors, seasonal and climatic factors, marriage and the age factor, progesterone meetings with individual factors, emotional factors and age, drug factors, genetic factors and so on. It is precisely because there are so many factors, how to achieve multiple birth pregnancy, even the experts are thorny.

3. More harm than good: for individual patients with infertility drugs after ovulation, pregnancy really have too many births phenomenon. Multiple birth pregnancy as a result of the excessive expansion of the uterus to cause uterine contractions and early childbirth. Clinical experience has shown that in the twin pregnancy, premature emergence of the military by the maternal is 45% ~ 65%, while as many primipara 75% ~ 80%. 3 or more premature births rate higher. In addition a multiple birth pregnancy fetal malnutrition often, because a "food" sub-people to eat, someone is bound to food, coupled with as a result of premature birth due to congenital deficiency, a relatively low survival rate of multiple births, if able to survive , body mass difficult to catch up with ordinary people.

4. Getting too much of: a multiple birth pregnancy is the music is sad, but also from the Kawasaki in the percentage of births was to find the answers. According to the World Health Organization statistics: a single incidence of fetal malformations was 1.4%, twins is 2.71%, and 3 as high as 6.9% of births. Wide variety of fetal malformations, and some with very serious consequences, such as abnormal posture, visceral defects, such as missing limbs, or as a result of intrauterine compression caused by the deformation and so on. Those conjoined infants, the parasitic fetus body in the fetus such as fetal causes are multiple births and pregnancy-related.