Fetus had rare condition affecting blood flow in the womb, expectant dad said. — -- An expectant mom getting ready to welcome two sets of identical twins -- a one in 70 million occurrence -- ...

New reproductive technologies have yielded a vast array of novel variations on the two conventional twin types—identical and fraternal—as well as some curious twin-like sibships. When a Canadian ...

Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are the same sex and share the same genes. Sometimes called paternal twins, identical twins ...