Fraternal twins are the result of two eggs getting fertilized in the same ovulation phase.
Identical twins are the result of a fertilized egg dividing into two. Although it is not possible to plan for twins, it has been observed that the use of fertility drugs does increase the chance of multiple births. This is because fertility drugs cause more than one egg to be released in a particular cycle. As women in developed societies delay childbearing, they seem to have trouble getting pregnant. All Rights Reserved Worldwide.