Abby and Brittany Hensel Abby and Brittany Hensel Abigail Loraine Hensel and Brittany Lee Hensel (born March 7, 1990) are American dicephalic parapagus twins; also known as conjoined twins. They are highly symmetric for conjoined twins, giving the appearance of having a single body without marked variation from normal proportions. Each has a separate heart, stomach, spine, pair of lungs, and spinal cord. Each twin controls one arm and one leg. As infants, learning to crawl, walk and clap required them to cooperate. They can eat and write separately and simultaneously. Activities such as running, swimming, hair brushing and driving a car require coordinated
Monochorionic twins Monochorionic twins Monochorionic twins are monozygotic (identical) twins that share the same placenta. If the placenta is shared by more than two twins (see multiple birth), these are monochorionic multiples. Monochorionic twins occur in 0.3% of all pregnancies. 75% of monozygotic twin pregnancies are monochorionic; the remaining 25% are "dichorionic diamniotic". If the placenta divides, this takes place after the third day after fertilization. Monochorionic twins generally have two amniotic sacs (called Monochorionic-Diamniotic "MoDi"), but sometimes, in the case of monoamniotic twins (Monochorionic-Monoamniotic "MoMo"), they also share the same amniotic sac. Monoamniotic twins occur when the split takes place after