A twin is one of two offspring (Children) produced in the same pregnancy and are generally identical or unidentical. Many believed giving birth to twins are most times hereditary as certain families always have twins in their progressive generations. 

  Biologically, twins are of two types

1. Two egg twin:This type of twin is formed when different egg cells are fertilised by different sperm cells with each fertilized egg developing into different individuals and are mostly unidentical. In this case, there is simultaneous fertilization of different eggs. 

2. One-egg twin: They occur when a single egg is fertilized and then divides either immediately or at some embryonic stage. 

  It have been said that the Yorubas have the highest twins in the world of about 45 to 50% in every 1000 birth. The reason is as a result of yams species they consume. Apparently this yam species (Discorea Spp) contains phytoestrogen, an estrogen compound that increases a woman’s Follicle Stimulating Hormone (FSH), and may induce a higher rate of ovulation. This phytoestrogen present in the yam causes release of multiple eggs during ovulation creating a chance for multiple fertilization. 

  Generally the world's highest rate of twins are across central Africa while the lowest in Latin America, South Asia and South east Asia.

  Eating of water yam does not guarantee 100% twinny but its worth trying as it contains this oestrogen hormone and eating in excess poses no direct harm to the body as compared to other synthetic drugs.

Other foods that contain phytoestrogen include Soybean, Garlic, flax, Oats Barley and wheat.

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