Researchers have long noticed that the Yoruba tribe — whose members live in Nigeria, Benin, Togo, and elsewhere — is a world leader in twins.
High parity – Having one or more previous pregnancies, especially a multiple pregnancy, increases the chances of having multiples. Race – African-American women are more likely to have twins than any other race. Asian and Native Americans have the lowest twinning rates.
In Australia, twins happen in 1 in every 80 births. This means that 1 in 40 Australians is a twin. The birth rate of identical twins is the same around the world and doesn't vary with the mother's age.
Vietnam was the country with the fewest twins (6.2 per 1,000 births) and Benin was the country with the most (27.9 per 1,000). Over time, some of these developing countries saw increases in twins, but some saw decreases and some stayed the same, with any changes tending to be small.
'The Land of Twins'
Just east of Benin, the westernmost regions of Nigeria have some of the highest twin rates in the world.
The rate keeps rising for (naturally) two big reasons. More twins are being born now than ever before. Parents are increasingly using in-vitro fertilization and deciding to have children later in life. The twin rate could continue to go up as more nations push these factors higher.
Australians Anna and Lucy DeCinque call themselves the “most identical twins in the world”, and work to live up to their self-proclaimed title. They're engaged to the same man, have the same bathroom schedule, and work the same job – one for a salary the other as a volunteer, for legal reasons.
Heredity – a woman is more likely to conceive fraternal twins if she is a fraternal twin, has already had fraternal twins, or has siblings who are fraternal twins.
The Science of Fraternal Twins. Mixed-gender twins are the most common type of fraternals, some 50 percent are boy-girl. To understand this combination: Males have XY chromosomes, females have XX chromosomes. You have a girl twin when the father's X chromosome combines with the mother's X chromosome.
IGBO-ORA, Nigeria — Twins appear to be unusually abundant in Nigeria's southwestern city of Igbo-Ora. Nearly every family here has twins or other multiple births, says local chief Jimoh Titiloye. For the past 12 years, the community has organized an annual festival to celebrate twins.
Septuplets (7)
The Frustaci septuplets (born 21 May 1985, in Orange, California) are the first septuplets to be born in the United States.
Octuplets are a set of eight offspring born at one birth. An individual that is part of such a set is called an octuplet.
Monoamniotic-monochorionic Twins
This is the rarest type of twin, and it means a riskier pregnancy as the babies can get tangled in their own umbilical cords. If you have monoamniotic-monochorionic twins, your healthcare provider will monitor your pregnancy closely.
The first wife (died ante 1770), of Feodor Vassilyev (b. 1707–c. 1782), a peasant from Shuya, Russia, gave birth to 16 sets of twins.
Central to the Yoruba people's diet are plants with a tuber root, such as yam and cassava. Some residents and experts in Nigeria believe that, due to the high phytoestrogen content in these plants, women are more likely to release more than one egg at a time, which usually leads to twin pregnancies.
The quick answer to this question is that, in a twin pregnancy, it is the mother's genes that determine twins. First up, giving birth to identical twins is not genetic, but conceiving fraternal twins is. The mother may have the genetic trait of releasing two eggs in one menstrual cycle.
Polar body twinning is thought to occur when an egg splits - and each half is fertilised by a different sperm. This results in twins who appear very much alike but share approximately 75% of their DNA.
If twins are a boy and a girl, clearly they are fraternal twins, as they do not have the same DNA. A boy has XY chromosomes and a girl has XX chromosomes. Girl-boy twins occur when one X egg is fertilized with an X sperm, and a Y sperm fertilizes the other X egg.
About one-third of twins are identical or monozygotic twins (when one fertilised egg divides in half). Two-thirds are non-identical or dizygotic twins (when two eggs are fertilised by different sperm). The chance of any woman having identical twins is one in 300.
It was found that many Aboriginal twin pregnancies and births are physically and practically challenging and the majority of multiples are born early and small.
In 2021, according to the Australian Bureau of Statistics (latest report as of October 2021) there were 4,248 multiple births representing 1.5% of all births (309,996) in Australia. This comprised 4,185 pairs of twins and 63 sets of triplets and higher order multiples.
In fact, one British study tested ESP potential among identical twins and found that they were correct about 25% of the time, the same as any other siblings. There is one particular power though which twins possess, longevity. Fraternal twins live longer than singletons and identical twins longer still.
In a rare but happy coincidence, identical twin sisters gave birth to their first-born children on the same day at the exact same time. We know being identical twins is unique. A pair of twin sisters has taken their bond to a whole new level.