Twin pregnancies in 1 out of every 80 pregnancies that occur
naturally. This rate increases even more in those who receive drug therapy for
pregnancy and especially in IVF studies.
Twins are divided into single twins (monozygotic) and fraternal
twins (dizygotic). Monozygotes are also called "identical" and
dizygotes are called "fraternal". One tenth of all twins are
monozygotic twins.
Dizygotic
twins (fraternal twins): Two egg cells are fertilized at the same time by 2
sperms. Their genetic makeup is not the same, so their sex and appearance may
be different. They are like two separate brothers who are in the mother's womb
at the same time.
There are always two placentae in them. The placenta and
amnions are different.
Monozygotic
twins (identical twins): Like single pregnancies, 1 egg is fertilized by 1
sperm, but will be divided later. The genders are always the same. Their
genetic structure is the same. If this division occurs within the first 3 days
after fertilization, diamniotic dichorionic (two amniotic sacs, two pleenta),
diamnionic monochorotic (two amniotic sacs, one pleenta), and monoamniotic
monochorionic (single amniotic sacs) between 9-13 days. single placenta)
becomes twin pregnancy. The most common diamniotic is monochorionic. Siamese
twins (conjoined twins) are formed as a result of divisions after the 13th day.
It is very important to have one or two
(monochorionic-dichorionic) plesentas in the follow-up of twin pregnancies.
Ultrasound performed around 11-15 weeks can be very useful for differentiation.
Increased
risks in multiple pregnancies:
- Miscarriage risk is higher.
- Preterm birth is more common.
- Preeclampsia and ectopia are more common during pregnancy.
- Nausea and vomiting are more common.
- Placenta anomalies are more common. Plesenta previai
detachment plesenta.
- Anemia is more common.
- Congenital (congenital) anomaly risk is higher (even more
in monozygotics)
- Serabral palsy (spastic handicapped) baby is more common.
- Twin to twin transfusion syndrome can be seen.
- Vanishing twin syndrome can be seen.
- Monoamniotic twins have a high risk of cord entanglement
and related intrauterine death.
Who is more
likely to have twin-triple pregnancy?
- It is more common in some races (about 5% in Nigeria)
- In pregnancies occurring in advanced ages (peaking at 37
years of age): It is more difficult to conceive at these ages compared to young
ages, but when conceiving, the rate of majority pregnancy is high.
- If the mother has a family history of twin pregnancies, the
chance increases (valid for dizygotic twins)
- Having a twin in the father's family does not affect.
- Multiparite
- In countries exposed to daylight, in summer
- In tall and overweight women
- Clomiphene citrate (about 10%) or in those who become
pregnant with gonadotropin treatment (20-30%)
- The chance of forming monozygotic (twin egg) twins is not
affected by any factor.
Normal or
cesarean birth ?
Normal or cesarean delivery decision may change according to
examination findings.
In pregnancies with more than two babies, cesarean is always
preferred.
What is
fetal reduction?
Fetal reduction is an attempt to reduce the number of fetuses
to reduce certain risks, such as preterm birth, low birth weight, and multiple
pregnancies in pregnancies with 3 or more fetuses in the uterus. For this, the
substance called potassium chloride (KCl) is given to the heart of one or more
of the fetuses via ultrasound via a fine needle from the mother's abdomen. The
fetus whose heart is standing shrinks over time (may be 4-5 weeks) and
disappears. The procedure is not harmful to other babies. In 4-5% of
pregnancies treated, there is a risk of pregnancy leading to complete abortion
with all fetuses.
The best time for this procedure is between 10-12 weeks of
gestation. The reason for not being able to be done in earlier weeks is
"to wait for the spontaneous termination of pregnancies if the development
potential is low or may end spontaneously." In the next weeks, if one or
two of the babies see a special problem and is thought to be incompatible with
life, this process is applied.
One of the
twins being dead and the other alive - Intrauterine death of the twin partner
(Twin partner ex)
When one of the twins dies in the womb. It is seen in 3-5% of
twin pregnancies. If one of the babies is dead, it may pose some risks for the
alive baby.
In this case, especially if the twins are monochorionic (if
the two babies have a single common placenta), the risk is higher for the live
baby. Serious neurological damage occurs 3-4 times more in living baby than
dizygotic twins. It is difficult to decide when to give birth. Conditions such
as how old the live baby is and whether it has completed its development affect
this decision. Whether twins are monochorionic (two babies have a single placenta)
or dichorionic (two babies have separate placenta) is a criterion that will
affect the decision of birth. Just because one of the twins is dead doesn't
always mean that the live baby should be delivered immediately. The decision
may vary depending on the obstetric condition in that patient. However, the
baby who lives in monochorionic twins is delivered at high risk because it is
at higher risk. In dichorionic twins, since the risk of harm to the living baby
is low, birth may be delayed more if necessary.
ADDITIONAL
INFORMATION:
- Valementous insertion (memrenous insertion) is more common
in twin pregnancies in the placenta.
- It is seen in TTTS and TRAP monozygotic twins.
- Fetus papyraceus is a condition that can be seen in both
monozygotic and dizygotic twins. It is the death of one of the fetuses before
birth and being flattened by crushing.
- The average gestation period in single pregnancies is 39
weeks, while it is 35 in twins, 32 in triplets and 29 in quadruplets.
- In twin pregnancies, B-HCG, AFP, Estradiol, Estriol,
progesterone levels are higher than normal pregnancies.
In twin pregnancies, preterm labor (preterm delivery),
PPROM, GDM (gestational diabetes), preeclampsia, anemia, detachment placenta,
uterine atony, placenta previa, postpartum hemorrhage are more common than
single pregnancies.
- Some of the physiological changes that occur in every
pregnancy occur more seriously in twin pregnancies. For example, increased
blood volume in the mother and anemia are more in twin pregnancies. Cardiac
output increases more than single pregnancies. The need for iron and folic acid
increases more.
- About 80% of women diagnosed with twin pregnancy in the
first months of pregnancy have twin babies. The other part gives birth to a
single baby due to the disappearance of one of the fetuses in the first
triemster.
- Presentation in twin pregnancies at birth is most
frequently observed as vertex-vertex (40%). Then, vertex-breech (25%) and
vertex-transverse (20%) are observed, respectively.
-WHAT SHOULD BE DONE TO HAVE TWIN PREGNANCY?
-IDENTICAL TWINS
-FRATERNAL TWINS
-TRIPLET PREGNANCY
-NORMAL BIRTH OR CESAREAN IN TWIN PREGNANCIES?
-TWIN TO TWIN TRANSFUSION SYNDROME
-CAN THERE BE TWIN BABIES FROM DIFFERENT FATHERS?
-CAN ANOTHER PREGNANCY OCCUR DURING PREGNANCY?
-VANISHING TWIN SYNDROME
-FETUS IN FETU (FIF)
-CHIMERISM
