History of Medicine Home > From 'Monsters' to Modern Medical Miracles Home > Embryology and Classification of Conjoined Twins Embryology of Conjoined Twins Identical twins develop when a single fertilized egg, also known as a monozygote, splits during the first two weeks of conception. Conjoined twins form when this split occurs after the first two weeks of conception. The monozygote does not fully separate and eventually develops into a conjoined fetus that shares one placenta, one amniotic sac, and one chorionic sac. Because the twins develop from a single egg, they will also be the same sex. The extent of separation and the stage at which it occurs determine the type of conjoined twin, i.e., where and how the twins will be joined.
History of Medicine Cesarean Section - A Brief History Preface Cesarean section has been part of human culture since ancient times and there are tales in both Western and non-Western cultures of this procedure resulting in live mothers and offspring. According to Greek mythology Apollo removed Asclepius, founder of the famous cult of religious medicine, from his mother's abdomen. Numerous references to cesarean section appear in ancient Hindu, Egyptian, Grecian, Roman, and other European folklore. Ancient Chinese etchings depict the procedure on apparently living women. The Mischnagoth and Talmud prohibited primogeniture when twins were born by cesarean section and waived the purification rituals for women delivered by surgery.