Lecture of twins (twins)

2021-03-21 12:00 AM

On the ultrasound, we see 1 vegetable cake, 2 amniotic fluid that has thin amniotic septum, no signs of Lambda. They are twins with 1 vegetable cake, 2 amniotic fluid and 1 ovary twins.

Definition of twins

Twins are a special case of pregnancy and are all thought to be a high-risk pregnancy because the morbidity and mortality rate of mother and infant is 2-3 times higher than that of single pregnancy.

Common conditions such as single pregnancy such as intrauterine growth retardation, multiple amniotic fluid in twins can also have some special diseases such as a higher rate of preterm birth and especially the rate of fetal toxicity. higher than pregnant one.

The rate of twins accounts for only about 1% in pregnancy, but due to the special nature of the pregnancy and its risk, prenatal diagnosis plays an important role in monitoring and prognosis in special twins. is a diagnostic classification of twins.

Classification of twins

(Also known as placenta essence and gametes essence) based on the type of gametes, they can be classified into the following types of twins:

Twin ovary twins

This is a type of twins that corresponds to two fertilized ovules with 2 separate sperm and it is a type of twins where two separate fetuses are located in one uterus (this is called true twins) and is a type of twins. 2 amniotic fluid and 2 vegetable cakes. It accounts for 2/3 of the number of twins or the overall rate is 6-7/1000 births.

Twins 1 ovule

This is a type of twins that a sperm fertilize with 1 ovule but divide into 2 pregnancies (it is called pseudo-twins), depending on the time of dividing into two embryos, people divide into parallel types. Different pregnancies, it accounts for 1/3 of the number of twins and with an overall rate of 3 - 5/1000 births.

Twins 1 ovule: Two amniotic fluid, two vegetable cakes.

This is a monocort, but the embryo division occurs very early on about 3 days after fertilization, the twins have a similar progression to the two ovary twins (2 placenta, 2 amniotic fluid. ), the rate of 24-27% of the number of single-ovular twins.

Single ovary twins: One vegetable cake and two amniotic fluid.

This is the type of twins where embryo division occurs between day 4 and 8 after fertilization and it has a relatively high rate of » 70% of single-oocy twins, which are twins. Attention is drawn because there are many complications of pregnancy (for mother and baby) that occur in this category.

Single ovary twins:   A vegetable cake and an amniotic fluid.

This is the type of twins in which embryo division occurs between day 9 and 13 after fertilization, which accounts for about 2% of the 1-oocyte twins.

Several types of conjoined twins: These are special cases of twins where embryo division occurs late after day 13 after fertilization and it accounts for about 1% of single-ovular twins. But a special case is twins with head stick, chest stick, stomach stick or especially, especially pregnant in pregnancy.

Diagnosis of twins

As mentioned above, the diagnosis of twins classification is very important and the classification is made in the first 3 months and must use ultrasound or in other words only ultrasound is capable of making the diagnosis. Twins can be classified, the rest can be done, but it is a retrospective diagnosis, so in this article we discuss quite carefully about the diagnostic ultrasound to classify twins.

Ultrasound to diagnose twins in the first 3 months

Using ultrasound, especially the vaginal probe, we can diagnose twins quite early at about 7 weeks and it is acknowledged that the best time to diagnose is at 7-12 weeks of gestation. and a maximum of 14 weeks, and after 14 weeks or more, the diagnosis is very difficult.

Diagnosis - ultrasound can be done very early with transvaginal ultrasound:

5-week pregnancy: In the case of 2-oocyte twins with 2 separate pregnancy bags, through ultrasound we can clearly see 2 pregnancy bags.

6-week gestation: We can see single-ovular twins with the appearance of two separate yolk sacs.

7 weeks gestation: We clearly see 2 separate embryos with two pictures of fetal heart activity.

After 7 weeks or 8-14 weeks: At this time, we can diagnose the type of embryo and placenta or in other words classify twins.

On the ultrasound, when we see 2 separate pregnancy bags, 2 separate vegetable cakes, it is the twin amniotic fluid, 2 vegetable cakes or 2 ovarian twins.

On the ultrasound we see 1 vegetable cake, 2 amniotic fluid and see a Lambda sign (that is, the junction between the two amniotic sacs has the same image as the word Lambda ( l ) in Greek) then we diagnose it fetus has 2 amniotic fluid, 1 vegetable cake, but it is twins with 2 ovules (because 2 vegetable cakes are close together)

On the ultrasound we see 1 vegetable cake, 2 amniotic fluid that has thin amniotic septum, no signs of Lambda. They are twins with 1 vegetable cake, 2 amniotic fluid and 1 ovary twins.


On ultrasound, there is 1 vegetable cake, 1 amniotic fluid and 2 separate embryos called twins, 1 vegetable cake, 1 amniotic fluid and 1 ovarian twins.

In addition, ultrasound can also show 2 different sexes and in that case the two ovary twins.

Ultrasound of the following months (quarter 2 - quarter 3) after 14 weeks

Ultrasound of twins can diagnose twins (1 oocyte, 2 oocytes) is not possible or is very large error. During this time, morphology diagnoses the fetal malformation (weeks 21-24) and monitors fetal development (weeks 30 - 32). Watch for complications of twins (Transfusion Syndrome).

Clinical diagnosis

Mechanical symptoms

The functional symptoms are nonspecific, but some authors describe them as:

Heavy vomiting: Severe vomiting, weight loss in the first 3 months.

The belly is bigger than usual.

Women experience heaviness or swelling of lower extremities due to pressure or weight gain in the last months of pregnancy.

See the fetus pedal in many different positions.

Physical symptoms

The first three months

Physical symptoms in the first 3 months are not as specific as in normal pregnancy.

The middle three months and the next three months

The uterus is much bigger than the gestational age (due to the height of the uterus, the waist circumference is much larger than the gestational age)

Outward, there are many parts of the fetus.

Hearing: Seeing that 2 fetal heart cells are located in 2 different positions, about 10-15 cm apart. The fetal heart rate also has different frequencies spaced> 10 beats.

Detection of signs of pregnancy toxicity such as edema, high blood pressure

Laboratory testing

The test for b hCG increased highly in the first 3 months but was also nonspecific.

Ultrasound: Has an important role in the diagnosis of twins as well as the diagnosis of twins classification as we have described above.

Other tests: Special tests to probe and rule out fetal toxicity such as proteinuria test.

Labor of twins

Twins are a high-risk pregnancy, especially known as a difficult delivery. Twins difficult delivery is due to the 2nd pregnancy and a number of other factors related to labor:

Twins' labor is often prolonged because the uterus is too big, so weak uterine contractions do not work to open the cervix, leading to slow opening of the cervix and prolonged labor leading to fatigue and fatigue in the mother. increase the risk of twins and the risk for the mother.

Abnormal pregnancy: Because the amniotic fluid with many uterus is larger than normal, the fetus is usually small, so it is common to encounter an abnormal fetal position such as the inverted throne, the horizontal or the first two are inserted into each other, making it not appear in the subframe. is a contributor to labor and is also a factor in prolonged labor.

Second pregnancy book: After the first birth certificate, the uterus becomes spacious and makes the 2nd fetus rotate, change position leading to abnormal formation, especially the horizontal or if not very It is common to have sa chi and a vegetable prolapse, so the second pregnancy is often difficult because there are many possible events.

After the first birth certificate the uterus shrinks and leads to placenta and if it is a vegetable cake, the risk of plucking makes the 2nd fetus at risk of major failure so the 2nd fetus has to give birth for a maximum period of time. 15 - 20 minutes after the first birth certificate.

The weight of twins is usually lower than giving birth to one fetus and is mostly preterm, so receiving and taking care of the twins must be done in the delivery room and be very urgent to avoid hypothermia caused by the fetus. small.

Twins delivery

Must prepare enough means of resuscitation and the necessary tools to intervene in pregnancy.

An intravenous line should be placed prior to delivery to be able to administer inotropic drugs (oxytocin) when needed.

Twins must have 2 people because: The first person takes delivery of the first and does the necessary movements of neonatal resuscitation of the first, then the second person must immediately examine the cervix, love state of the amniotic fluid and especially check the throne of the 2nd fetus no matter what, the first step is to press the amniotic fluid if there is still the amniotic fluid to fix the fetus if it is the first or inverted to prevent the crown from turning into the throne abnormalities and avoid spawning. Immediately rotating the fetus if it is horizontal to pull the fetal leg down becomes inverted, so the second person is very important and necessary to avoid the events of the second pregnancy.

Period of vegetable book: This is an important period because many complications can occur at this stage:

Vegetable sauce: Because the vegetable cake is large, the vegetable book is often not complete. The vegetable cake must be carefully checked. If necessary, it is necessary to specify uterine control immediately.

Bleeding due to uterine sputum: The uterus is dilated ... during pregnancy, when labor is often long, so it is easy to feel the uterus after giving birth because the uterus cannot contract, so it is necessary to control the uterus and give medicines. increase uterine contraction by intravenous line.

Bleeding from genital tract trauma: This is more likely to happen in single-pregnancy birth because twins often require intervention in the second pregnancy, so it is necessary to check postpartum software such as the cervix - the vaginal wall.

Postpartum: Like having a single pregnancy, postpartum monitoring is nothing special.

Indicated cesarean section

Indications for cesarean section in twins currently tend to increase gradually due to the rate of multiple pregnancies due to the use of assisted reproductive methods, so the possibility of cesarean section is very high, not to mention cesarean section of mothers when twins are infected pregnancy toxicity or some complications of twins. Remaining indications cesarean section for pregnancy in accordance with general indications such as single pregnancy.

Complications of twins

As we have presented: twins are a high-risk, high-risk, and high-risk pregnancy. Common complications of twins, such as during single pregnancy: threat of preterm delivery and preterm delivery or such as fetal toxicity, diagnosis and treatment are also done in single pregnancy (see sections for threats of preterm delivery and pregnancy). premature birth, poisoning during pregnancy). In this article we present only the specific complications of twins.

Blood transfusion syndrome

Transfusion syndrome occurs in 1% of twins and is responsible for 12% of perinatal mortality and 17% of morbidity in the perinatal period of twins. This is a special disease that only occurs in twins with 1 ovule: 1 vegetable cake, 2 amniotic fluid with the rate of 5 - 24%, not occurring in twins with 2 vegetable cakes, 2 amniotic fluid.

As for twins with 1 vegetable cake, 1 amniotic chamber, people do not have transfusion syndrome even though they have the connection of the circulation.

The cause of the blood transfusion syndrome is due to the continuation of the circulation between the two fetuses in the vegetable cake, the severity of this syndrome depends on the nature of the continuity of the circulation, there are 3 forms: dynamic connection. arteries - arteries, connecting arteries - veins and the connection between veins - veins. The cyclic continuation in the placenta occurred in 100% of the twins 1 vegetable cake with 2 amniotic fluid and 87-91% in the twins 1 vegetable cake with 1 amniotic chamber and never in the twins with 2 placenta amniotic fluid.

Time to happen blood transfusion: as early as 20 weeks and at the latest after 30 weeks. Usually it happens about 24-27 weeks. The sooner the transfusion syndrome occurs, the worse the prognosis.

Symptoms and diagnosis

Usually the diagnosis is mainly based on ultrasound. In a case of twins with 2 amniotic fluid 1 vegetable cake appear:

An amniotic fluid with little amniotic fluid, a small fetus and a small fetal bladder.

One amniotic fluid is poly amniotic fluid, the fetus is enlarged and the fetal bladder is enlarged.

2 unbalanced fetuses.

Seeing a small atrophy and an edema, if it does, the prognosis is very bad

Umbilical artery doppler: in the fetus with little amniotic fluid, the RI = 1. In contrast, it is normal in the other fetus.

Differential diagnosis

It is not transfusion syndrome when only: there is a difference in the size of the fetus.

When a fetus has poly amniotic fluid and a single minimal amniotic fluid

When we see a small, atrophy, a fetus is reduced to an angle and a normal fetus

The ultimate consequences of the blood transfusion syndrome

Premature due to poly amniotic fluid.

1 fetal death (that is a fetus to donate blood), 1 fetus that is a fetus receiving blood and the prognosis of 2 fetuses is both bad (occurring in 40% of cases with transfusion syndrome)

Progression very badly if transfusion syndrome appears before 28 weeks. 100% of cases are unable to keep the pregnancy.

Treatment of blood transfusion syndrome

So far there is no specific treatment, but only a few temporary methods of treatment are described:

Breaking the septum to clear the amniotic fluid between the two amniotic fluid.

Laser burning of the connected blood vessels on the shallow part of the cake.

Minimize pregnancy by killing a fetus with a serious condition.

Amniocentesis periodically.

Subscribe syndrome blood transfusion need to use ultrasound and prognosis rather if the evolution of the syndrome occurs late and can get pregnant if as gestation prognosis can birth is usually after 36 weeks ® has can be monitored weekly ultrasound.

General Prognosis: Since blood transfusion has occurred, prognosis for both pregnancies is poor.

Twins 1 stillborn

Stillbirths with 1 fetus occur in 7% of twins and occur more in unborn twins (1 vegetable cake, 1 amniotic fluid or 1 vegetable cake, 2 amniotic fluid) with the rate of 6.8% in twins. 1 oocyte and 2.8% in 2 ovary twins.


Common maternal causes include pregnancy toxicity, pre-eclampsia, diabetes, or infection.

The specific causes of twins: Mainly the syndrome of blood transfusion (twins with 1 vegetable cake, 2 amniotic fluid) 2 umbilical cord in close proximity or umbilical cord of twins with 1 vegetable cake, 1 amniotic fluid.

Causes of pregnancy: fetal malformations, delayed fetal development in the uterus ...

Consequences of stillbirth

On the maternal side: As with single pregnancy, it carries a risk of bleeding due to decreased fibrinolysis or intravascular scattered coagulation syndrome (CIVD).

On the child side: The consequences on the child side will be very different depending on the type of twins: For twins with two veggies with no circulatory continuity, the consequences for a living fetus are generally nothing special. On the contrary, if there is a continuation of the circulation in the twins with 1 vegetable cake (1 amniotic fluid or 2 amniotic fluid), the consequences for the living fetus are quite severe:

The decomposed substances of the fetus die through the circulatory system of the living twins, causing special disorders of the coagulation process.

The living fetus has to pump blood to the dead fetus through the general circulatory system, causing it to have a severe shortage of circulating volume leading to feeding anemia and eventually stillbirth in 27-30%. Anemia leads to lack of oxygen and damage to some organs and leave sequelae in these organs in 45% of cases, of which: 75% of brain damage, 28% of damage to digestive organs, 24 % kidney damage and 8% lung damage.

Treatment attitude

For twins with 2 vegetable cakes - 2 amniotic sac without the circulatory continuity: In theory there will be no danger to the live fetus, but need to monitor the live fetus by recording fetal heart rate, monitoring Doppler live pregnancy and taking the pregnancy when able to feed (> 37 weeks) or get pregnant if the cause of the fetal death is due to systemic causes of the mother. When the cause of fetal death is not clear, it is necessary to closely monitor the fetal heart rate, doppler and take the pregnancy when the fetus is> 37 weeks old.

For twins with 1 vegetable cake (2 amniotic fluid or 1 amniotic sac) with the circulatory continuity, the prognosis of surviving pregnancy is not good and the risk of damage to organs, leaving dangerous sequelae always occurs. so monitoring of fetal survival must be very close.

Family information about the risk of a live fetus

It has been found that organ damage occurs 2 weeks after the first fetus dies so one can wait up to 2 weeks to decide on a second pregnancy if gestational age permits.

Suspension of pregnancy if the gestational age is too small because of the risk of serious complications to the live fetus.


With twins, it is important to keep in mind that pregnancy is a high risk to the mother and the fetus.

Diagnosis of embryo and vegetable cake classification is very important and needs to decide on the attitude of managing and monitoring the prognosis of twins.