What is a dichorionic diamniotic DCDA twin pregnancy?

A dichorionic diamniotic (DCDA) twin pregnancy is a type of twin pregnancy where each fetus has its own separate placenta (dichorionic) and its own amniotic sac (diamniotic). This arrangement typically occurs when two separate eggs are fertilized and implant in the uterus, leading to fraternal twins. DCDA pregnancies are considered the lowest risk type for complications compared to other twin pregnancies, as each twin has its own placental and amniotic environment.