According to various estimates, today in the world there are from 70 to 80 million pairs of twins.

The number of twins born in relation to the total number of newborns in different countries and on different continents is different, but in general the trend is such that it continues to grow. Compared with the 60s, the percentage of twins has increased from 1.18 to 2.78, that is, almost 2.5 times. Much is said about the reasons for this phenomenon, and among the main reasons are the successes of modern medicine in the field of infertility treatment. (For more on why, see Who gets twins and can I have twins?)

In the early 1980s, there was one twin for every 80-90 births.
In the late 1990s, there was one twin for every 40-45 births.

In the early 1980s, there were one triplets for every 6,400 births.
In the late 90s, there were one triplets for every 800-1300 births.

How often are twins born from representatives of different countries and peoples?

In the US, there are 1 pair of non-identical twins for every 100 people in the population.
and for every 300 people - 1 pair of identical twins.

1/3 of all twins born in the US are identical. In Japan, the proportion of identical twins is 2/3 of all twins.

Hellin's law

According to the pattern derived by American scientists, the frequency of the birth of twins before new methods of treating infertility was as follows:

More than one pair?

If you already have non-identical twins, the chances of getting a second pair are doubled. This is due to the fact that the body of a woman who once conceived dizygotic (non-identical) twins without the use of medications is able to produce several eggs during the period of ovulation.

If you are a twin (if you have twins in previous generations)...

Dear women! According to many studies, "twinhood" can be inherited (maternally). So, -
If you are a non-identical twin, you have about a 6 in 100 chance of having twins.
If you are an identical twin, you have exactly as many chances as any other woman (from 1 to 2.5 chances out of 100, depending on the use of hormonal drugs).
If your mother is a non-identical twin, your chances are above average.
If your father is a non-identical twin, then the chances are average, just like if your husband is a twin, or has twins in the pedigree.
If either of your parents is an identical twin, this will not affect your chances in any way.

Gender of twins

Unfortunately, such data are extremely rare, so we are content with statistics for Canada and the United States.

More about the trend

As the average age of women giving birth continues to increase (especially in developed countries), the likelihood of more twins being born is also increasing. In 1990, 39 women aged 45-49 in the United States became mothers of twins. In 1997, there were already 444. From 1980 to 1996, not a single woman aged 50-54 gave birth to twins. In 1997, 50 women of that age gave birth to twins and 13 to triplets.

But the main reason for the increase in the frequency of twin births continues to be the development of infertility treatments. Modern research shows that 80% of triplets were born as a result of the use of such methods.

The flip side of the increase in twin births is more underweight babies and preterm births, which in turn lead to higher infant mortality rates. In terms of statistics, the risk of premature birth and the birth of children of too small weight (before 1500) in the case of twins is 8 times higher, and with triplets 33 times higher than in the case of the birth of one child. In 1998, 41.7% of twins and 89.1% of triplets were born premature or very low birth weight.

(Trends in Twin and Triplet Births: 1980-98, by Joyce A. Martin, M.P.H. and Melissa M. Park, B.S. Division of Statistic)

Do you know that....

The usual duration of pregnancy is 39-40 weeks, in the case of twins 36 weeks, with triplets 33-34 weeks, with quadruples 30 weeks, with quintuplets 28-29 weeks.

18-22% of twins are left-handed (in non-twins this percentage is 10).

Identical twins have similar encephalograms.

The science that studies twins is gemellology.

Often, twins talk to each other in a language that is not understandable to others. This phenomenon is called cryptophasia.

Which was published online on September 6, 2016. in the BMJ, to minimize the risk of perinatal mortality, delivery in uncomplicated dichorionic twin pregnancies should be discussed at 37 weeks' gestation. The authors of the meta-analysis also did not find convincing data that could justify the practice of delivery before 36 weeks in monochorionic twin pregnancies. This meta-analysis is the largest study currently available on the incidence of stillbirths and other neonatal outcomes in twin pregnancies and was the first to examine neonatal mortality as a function of gestational age. These estimates of neonatal mortality at different gestational ages are important information for planning delivery in multiple pregnancies.

Twin pregnancies are known to be associated with a higher risk of stillbirth compared to singleton pregnancies, and this risk increases with increasing gestational age. A fairly common practice aimed at preventing stillbirth in uncomplicated multifetal pregnancies is early planned delivery, but preterm birth also leads to an increase in complications in newborns.

Currently, there is no generally accepted point of view on the optimal timing of delivery during pregnancy with twins. Various current recommendations mention 34 to 37 weeks of gestation for monochorionic twins, when the placenta is shared, and 37 to 39 weeks for dichorionic twins, when the placentas are different.

For this meta-analysis, the researchers conducted a systematic review of studies that had been published in any language up to December 2015. Then, a meta-analysis was performed to assess the risk of stillbirth and complications in the neonatal period in monochorionic and dichorionic twins at different times, starting from 34 weeks of gestation, with an interval of 1 week. Included studies were also assessed for representativeness and risk of bias. Neonatal mortality was defined as death within 28 days of birth.

A total of 32 studies were included in the analysis, covering 35,171 twin pregnancies (29,685 dichorionic and 5486 monochorionic twins).

In dichorionic twins at 37 weeks' gestation, the risk of stillbirth with expectant management balanced the risk of neonatal death by delivery (pooled difference between risks, 1.2/1000 pregnancies; 95% CI −1.3 to 3.6; I 2 = 0%).

After 37 weeks, the risk of stillbirth significantly outweighed the risk of neonatal death due to delivery. Delaying delivery by as little as 1 week (up to a full 38 weeks) resulted in an additional 8.8 perinatal deaths per 1000 pregnancies (95% CI, 3.6 to 14.0 deaths per 1000 pregnancies; I 2 = 0%).

In monochorionic twins at 34 and 35 weeks, the risk of neonatal death was higher than the risk of stillbirth, but this result was not significant. At 36 weeks, there was a non-significant trend towards a higher risk of stillbirth compared to the risk of neonatal death (pooled difference between risks, 2.5; 95% CI −12.4 to 17.4/1000; I 2 = 0% ).

Rates of complications in the neonatal period, including the need for assisted ventilation, hospitalization in the neonatal intensive care unit, the frequency of respiratory distress syndrome and sepsis, steadily decreased with increasing gestational age in both mono- and dichorionic twins.

The authors of the analysis speculate that the policies adopted in many places for planned early delivery of multiple pregnancies may have led to a decrease in the number of full-term twins born, so that the risk of stillbirth at term may actually be even higher.

The information obtained on fetal and neonatal outcomes in twins of different gestational ages should be taken into account when planning the timing of delivery of individual patients, as well as when developing national and international measures to reduce the incidence of stillbirths and unexpected neonatal complications in infants born close to term.

Thus, this meta-analysis generally confirmed the information obtained in earlier studies and provided additional rationale for the current recommendations of the UK National Institute for Health and Clinical Excellence (NICE) for the management of twin pregnancies. Of course, the timing of delivery in multiple pregnancies should be chosen individually, but the available evidence base indicates that with uncomplicated dichorionic twins, delivery should be considered at 37 weeks, and with monochorionic twins, starting at 36 weeks.

Birth of twins is a fairly common occurrence. For many centuries, scientists have been struggling with the question of what determines the birth of twins in a particular woman, but they have not been able to find an unequivocal answer to this question, although most associate this with genetic predispositions, and also, oddly enough, with the age of the mother.

According to some reports, age is an equally important criterion affecting the birth of twins, triplets, etc. Statistics confirm that the largest number of twin births was noted in mothers aged 37-38 years, and after this age, the number of multiple births was greatly reduced. Of course, statistics do not take into account such a phenomenon as multiple pregnancy as a result of IVF.

According to some scientists, the frequency of birth of twins and twins depends to some extent on where their parents live. In countries with a temperate climate, the frequency is slightly higher than in countries with a hot climate, according to a group of specialist scientists.

In 1895, the French biologist D. Ellin formulated regularity in the birth of twins, according to which one twin accounts for 85 normal births, one triplets for 85 twins, 4 twins for 85 triplets, etc. Simply put, twins account for 85 births, triplets for almost 7,000 births, quadruplets for 680,000 births, and one gear (and this happens!) For 4,712,000,000 births.

multiple birth statistics

In Austria, a certain Mrs. Scheinberg gave birth 27 times, gave birth to 69 babies, and 4 times she had 4 children, 7 times 3 and 16 times 2.

Another Austrian gave birth to 3 twins, 6 triplets and 2 quadruplets in 11 births.

For many years in Russia, in one of the clinics, a lady was under the supervision of doctors who gave birth to 6 twins, 7 triplets and 4 quadruples (total: 49 children).

In 1755, Yakov Kirillov, a 60-year-old peasant from the village of Vvedensky, was presented to the court of Empress Elizabeth. He was married a second time, his first wife gave birth to 57 live children in 21 pregnancies, the second - in 7 pregnancies gave birth to 15 children, in total Kirillov had 72 children from two wives.

The Spanish shepherd from the province of Córdoba, José Pulido, was already awarded the Father of the Year award at the age of 107. His three wives bore him 36 children: the first - thirteen, the second - eleven, the third - twelve.

In the late 70s of the last century, according to Muslim customs, the Sudanese Bishara Mohammed el Shayeb married four women. All four spouses bore him two sons.

Scientific literature data indicate that by the end of the Second World War, a little more than 6 cases of the birth of 6 twins were known. However, in 1965, six twins were born in Humante (Brazil). In the district of Faridipur (Pakistan) in 1967, a young woman gave birth to six boys. In 1974, Suzanne Roznkowitz (25 years old) from the town of Kopstadt (Germany) gave birth to 3 girls and 3 boys at a time. In 1983, a woman from Blankenberge (Belgium) gave birth to six babies (5 boys and one girl).

But six children at a time is not the limit. In the German city of Chamelon there is a bas-relief with the caption: "When the year 1600 went, on the ninth of January in the morning, she gave birth to two boys and five girls." Although, apart from the bas-relief, there is no documentary evidence of this fact.

But at the beginning of the 20th century, 6 cases of the birth of 7 twins were already officially registered. Medicine claims that there are known cases of birth and eight twins, but this is already hard to believe.

In the same way, one does not believe in the birth of more children, but so far the only reliable case of the birth of nine children is known, of which two were born dead. On June 13, 1971 at the Royal Hospital in Sydney, 19-year-old Geraldine Broderick gave birth to 9.

Oddly enough, multiple pregnancy is not such a rare occurrence. If they were collected from all over the world in one place, then this number could be the population of two Frances! More than 100 million twins live on earth, and in Moscow alone there are at least 70 thousand couples. For every 100 newborns, there are one or two twin pairs. The record number of twins is born in Africa (in some tribes, every twentieth birth is multiple), the smallest is among representatives of the Mongoloid race.

Moreover, the number of multiple pregnancies is increasing. The statistical likelihood of getting twins or even triplets has been on the rise in recent years. Ten years ago, it was about 1:85, and now for every fifty births there is one twin or triplet. The number of quadruplets also increased: for example, in Germany from 1950 to 1983, quadruplets were born only 19 times, and in five years from 1983 to 1989 there were already 56 of them. A clear upward trend!

There are two reasons for the increase in the number of multiple births: women between 35 and 40 years of age are always more likely to give birth to twins than women younger than 35. Why this is so is not known, but it is an undeniable fact that there are now many more “late mothers” than another twelve years ago. However, the most important reason for the increase in multiple pregnancies is infertility treatment. If ovulation is stimulated by medications, then two or more eggs mature at the same time, and then fertilized at once. An increase in the number of triplets or quadruplets can be associated with hormonal treatment with absolute certainty.

In the occurrence of multiple pregnancy, the role of heredity is beyond doubt. So, in 31 out of 300 women in labor with a history of twins, relatives had indications of multiple pregnancies. Multiple pregnancy - the simultaneous development of two or more fetuses (twins). Its frequency ranges from 0.4 to 1.6%, but in recent years these figures have been increasing due to the use of drugs that stimulate ovulation (clomiphene, pergonal, etc.). The likelihood of multiple pregnancy increases with the age of the mother. Pregnancy with twins is observed most often and is 1:90, the frequency of three twins increases to 1:902, four - up to 1:903. Boys predominate among born twins.

The frequency of twin births may be related to the affiliation of the spouses to a particular ethnic group. So, in China it is 3:1000 live births, in Scotland - 12.3:1000, in Nigeria - 57.2:1000. These differences are associated with fluctuations in the frequency of the birth of fraternal twins, since the birth of identical twins around the world is kept at about the same level (3.5: 1000).

With the development of ultrasound methods and their application to determine the state of pregnancy, it has become apparent that the frequency of multiple pregnancy in humans can be higher than the numbers just given indicate. In fact, the rate of multiple pregnancy in developed countries is as high as 20:1000 pregnancies. In about 50% of cases, multiple pregnancy is not recognized, the reason for this is the high frequency of spontaneous abortions in the early stages in some women and spontaneous resorption of one of the amnions in others.

Multiple pregnancy is risky for both mother and children. In this article, you will find a summary of multiple pregnancy statistics, the numbers of which may scare you. If you are expecting twins, for you this statistic is just an excuse to take your condition more seriously and carefully observe your doctor, without neglecting examinations, examinations and necessary consultations. Medical supervision and timely action by doctors is the best way to avoid complications or at least minimize their consequences.

1. In developed countries, perinatal mortality (mortality shortly before childbirth, during childbirth and immediately after them) during multiple pregnancy is 5 times higher than during normal pregnancy with one fetus. Causes of miscarriage, frequent malformations, preeclampsia in the mother, incorrect presentation and birth trauma.
2. The birth of children with very low body weight in multiple pregnancies exceeds the frequency of this pathology in singleton pregnancies by 10 times.
3. The death of newborns in the first month of life exceeds that among the population by 7.1 times.
4. Mortality in childhood is 5.4 times higher.
5. Premature birth with twins occurs in 54% of cases, while with singleton pregnancy only in 9.6%.
6. 50% of children have a birth weight of less than 2500 grams, with a singleton pregnancy with low birth weight, 6% of children are born. The more fetuses, the lower the birth weight.
7. The frequency of congenital malformations: - with a singleton pregnancy 1.47% of cases - twins 2.17 cases - triplets 3.7% of cases
8. The second fetus always has a lower Apgar score, it often needs resuscitation, tracheal intubation.
9. Mortality in monozygotic twins is 3 times higher than in dizygotic twins
11. Among monozygotic twins, 1% are monochorionic, monoamniotic.
12. Mortality in monoamniotic monochorionic twins reaches 50%
13. Mortality with triplets reaches 50-108 children out of a thousand born.
14. The death rate for a quadruple is at least 67 children per thousand born, but the numbers are not accurate due to the rarity of such births.
15. Among all children with cerebral palsy, 5-12% are children from twins.
16. In multiple pregnancy, the risk of complications in the mother is also higher.

Thus, even according to the statistics of developed countries, multiple pregnancy is a high-risk pregnancy, the course of multiple pregnancy in countries with a low level of development of medical care is accompanied by even more depressing outcomes. In order to choose the optimal obstetric tactics (for example, embryo reduction), it is important to make a diagnosis of multiple pregnancy in a timely manner, very early.