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 ...

Although there are some rare exceptions, identical twins are almost always the same sex. Because identical twins occur when a single fertilized egg splits and forms two embryos, each embryo has the ...

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 ...

Carrying a twin pregnancy is not an uncommon event. It occurs when the uterus carries two fetuses simultaneously rather than one. Having twins runs in some families and age also appears to be a ...

There’s something fascinating about twins. The idea of two babies growing together often captures people’s curiosity. Many couples even wonder if there’s a way to plan or boost their chances of having ...

Mono-mono twins are an incredibly rare type of identical twins who share both a placenta and an amniotic sac. While this makes for a high-risk pregnancy, advances in monitoring and treatment have ...

Driven by curiosity, Diana and Martin Williams subjected their twin 3-year-old girls to a DNA experiment. Dressed in little pink coats, with white ribbons tied neatly in their curly hair, Alexa and ...