If the number of babies is two or more, it is called multiple pregnancy. In multiple pregnancies, twin pregnancies are more common and twin pregnancies are divided into monozygotic and fraternal twins. Expectant mothers and fathers, who learn that they have a multiple pregnancy in the later stages of pregnancy, are curious about the risks of multiple pregnancy as well as the difference between monozygotic and fraternal twins. In this article about multiple pregnancies, you can learn about the risk factors, the mode of delivery of multiple pregnancies and the things that expectant mothers should pay attention to for their own and their babies’ health.
The simultaneous fertilization of more than one egg or the formation of separate embryos by two or more dividing cells from a single egg is called a multiple pregnancy. The most common multiple pregnancy is twin pregnancy. Multiple pregnancies occur in 3 out of every 1000 pregnancies. However, recently, this rate has increased with the application of treatment methods such as assisted reproductive in vitro fertilization. Another factor in the increase of multiple pregnancies is the advancing gestational age. Women over the age of 35 or with a family history of multiple pregnancies are more likely to have multiple pregnancies.
Identical Twins (Monozygous Twins)
Identical twins, formed by the splitting of a single fertilized egg, are also called monozygous twins. Since identical twins carry the genetic information of the same sperm and egg, their physical characteristics are also the same, so it is very difficult to distinguish most identical twins from each other. In identical twins, which occurs in 1 out of every 250 pregnancies, how long after fertilization the egg splits into two is also a factor that makes a difference. If division occurs within the first 72 hours after fertilization, two amniotic membranes and two placentas are formed. If division occurs between 4 and 8 days, two amniotic membranes and a placenta are formed. In the division that occurs on the 8th day, an amniotic membrane and a placenta are formed; this condition accounts for 1% of monozygotic twins. However, in splits that occur after the 8th day, Siamese twins (conjoined twins) occur.
Fraternal Twins (Dizygotic Twins)
Fraternal twins are formed when two separate eggs are fertilized by two separate sperm. Dizygotic twins, who are not genetically identical, also differ from each other in appearance. While 30% of fraternal twins are of different sexes, 70% can be of the same sex. According to studies, the physical characteristics of fraternal twins can be as different as those of children born to the same mother and father at different times. Fraternal twins account for about 75% of multiple pregnancies.
Factors Increasing the Chance of Multiple Pregnancy
Women who have 4 or more children or are over the age of 35 are three times more likely to have multiple pregnancies than women under the age of 20 who do not have children. The height and weight of the mother is also a factor affecting multiple pregnancy. Tall and overweight women are more likely to have multiple pregnancies.
A mother with fraternal twins is twice as likely to have a multiple pregnancy than a singleton pregnancy. This shows that genetic factors are effective in multiple pregnancies. The fact that the mother is a twin is more effective than the father’s being a twin. So much so that if one of the fraternal twins is a boy, the probability of this person’s children being twins is 1 in 125.
Treatment methods applied in cases of infertility and inability to conceive have also significantly increased the number of multiple pregnancies. However, with the new law that came into force in Turkey in 2010, it is prohibited to place more than one embryo in the uterus, except for special cases. This situation has also reduced the multiple pregnancies that occur with the in vitro fertilization method.
Multiple Pregnancy Symptoms and Diagnosis
In multiple pregnancies, the abdomen is larger than in singleton pregnancies.
The expectant mother may gain more weight compared to singleton pregnancies. However, excess weight gain can also occur for other reasons.
Vomiting and nausea are more common in multiple pregnancies.
Due to the pressure applied to the bladder, the urge to urinate occurs more in multiple pregnancies.
The size of the uterus is larger than in singleton pregnancies.
Iron deficiency can be seen in pregnant women who have had multiple pregnancies.
Weakness and fatigue are more intense than in singleton pregnancies.
B-HCG value may be higher in multiple pregnancies. However, a high value does not necessarily mean that there is a multiple pregnancy.
The most accurate way to detect multiple pregnancy is ultrasound. After the 6th week, the number of babies can be seen clearly in the ultrasound imaging that will be performed under the control of the doctor.
Multiple Pregnancy Risks
There is a higher risk of preterm birth in multiple pregnancies compared to singleton pregnancies. Birth; While it occurs between 37 and 42 weeks in a normal pregnancy, it occurs before 37 weeks in 60% of twin pregnancies and 90% of triplet pregnancies.
My son also causes babies not to be born at a healthy weight; This may cause some health problems. Premature babies may have trouble breathing on their own and being resistant to infections.
Preeclampsia, also known as pregnancy poisoning, can affect the kidneys and liver as well as cause high blood pressure. Preeclampsia, which can be diagnosed by detecting protein in the mother’s urine, is a condition that jeopardizes the health of the baby as well as the mother. In pregnancy poisoning, where the risk increases with the number of babies, expectant mothers who are pregnant with identical twins have a higher risk than mothers who are pregnant with fraternal twins.
Although twins were seen in the first ultrasound scans, one of the babies may not be seen after a while. This condition is called “Disappearing Twin Syndrome”. In the first three months, after the development of one of the babies is stopped and lost, the surviving baby is usually born healthy. The most common symptom of this syndrome is bleeding from the uterus at the time of the syndrome.
Transfusion syndrome, which is usually seen in identical twins, is the vascular transmission between babies. In this case, one baby gets more blood flow while the other baby gets less blood flow. As a result, growth retardation and anemia may occur in the baby with low blood flow.
Other risky conditions that can be seen in multiple pregnancy are as follows:
The risk of birth defects in babies born with a multiple pregnancy is higher than in babies born with a single pregnancy.
Since blood cell production is faster in multiple pregnancies, the need for iron and folic acid increases. Anemia due to multiple pregnancies is 10-20% higher than in singleton pregnancies.
Gestational diabetes is more common in multiple pregnancies. This form of diabetes leads to some ailments such as respiratory distress in infants.
Since the placental surface and uterus are wider than in singleton pregnancies, the amount of bleeding is higher during and after delivery.
Multiple Pregnancy Delivery Type
The factors that determine the mode of delivery in multiple pregnancies are the number of babies, the position of the babies and the structure of the pelvis. The preferred mode of delivery for triplets or quadruplets is cesarean section. However, in twin births, babies come with their heads and the mother’s pelvis structure is not narrow, allowing normal birth. If there is a difference of more than 20% between the weights of the babies, the babies weigh less than one and a half kilograms, they do not come with the head, there are placental disorders and conjoined twins, the birth should definitely be cesarean section.
Although there has been no increased risk in normal delivery in recent years, an increase in cesarean deliveries has been observed in multiple pregnancies. The reason for this is both to keep the mother away from the stress of birth and to protect the babies from the risks that may occur during birth.
Considerations in Multiple Pregnancy
Regular doctor check-up is important in every pregnancy. However, mothers with multiple pregnancies should pay more attention to doctor control. Controls are important to prevent multiple pregnancy risks. At the same time, supplements should be used as required by the tests, and precautions should be taken against anemia and other health problems, if any.
In multiple pregnancies compared to singleton pregnancies, expectant mothers should be on leave earlier if they are working. The risk of preterm birth can be minimized by resting the mother.
Another factor that reduces the risk of preterm birth is that the mother consumes plenty of water. Since the need for water will increase as babies grow, consuming 2-2.5 liters of water a day will positively affect the healthy functioning of the mother’s kidneys.
As in every pregnancy, sleep pattern should be given importance in multiple pregnancy.
Protein and calorie needs are higher in multiple pregnancies. It is important for the expectant mother to pay attention to her nutrition in this sense and to seek advice from the doctor if necessary.