Normally a woman delivers only one child at a time. This child can either be a male or a female. Sometimes, however, two or more children are born at a time. Two children born of the same mother at one time are known as twins. Do you know how twins are born?
Between the 10th and the 18th day from the onset of menstruation, the reproductive organs of the female produce an egg called ovum. If during this period a female mates with a male, one of the male sperms enters into the ovum. This union of the ovum and sperm is known as fertilization and the female is said to have become pregnant. Two hundred eighty days later, the woman gives birth to a child.
But sometimes after the conception the ovum divides itself into two parts. Both these parts develop in the womb separately as two embryos. As a consequence, such a woman delivers two children simultaneously. The two children so produced are similar in complexion and appearance. Most of their traits are similar. Both the children will always be either boys or girls. This is because they are produced from the same ovum. Such twins are called identical twins.
Sometimes there is another possibility too. Two sperms from the male semen enter separately into two ova of the same female. This leads to the development of two embryos in the womb and the woman delivers two children. The children so produced may be different from one another. They may or may not have the same sex. Their other habits may also differ. Such twins are called n0n-identical or fraternal twins.
Sometimes we come across the term ‘Siamese twins’. The term Siamese for conjoined twin is derived from the famous celebrated twins, Chang and Eng-Bunker born in Mecong, Siam (now Thailand) in 1811. They were joined by cartilaginous band at the chest. Both of them died in a gap of three hours at the age of 62 in 1874. However, such twins are very rare.
Some women have given birth to more than two children at a time. On 22nd April, 1946, a woman in Brazil gave birth to ten children at a time – 2 boys and 8 girls. Spain and China also hold record of having women who gave birth to 10 children at a time. On 13th June, 1971 Mrs. Geraldine Broderick gave birth to nine children in the Royal Hospital of Sydney (Australia). Five were boys and four, girls. Of course, we often hear of women giving birth to 3, 4 or 6 children at a time.