"A dizygotic twin pregnancy always results in dichorionic diamniotic pregnancies. This feature alone cannot be used to distinguish dizygotic from monozygotic pregnancies as approximately 20% of monozygotic pregnancies will also be dichorionic diamniotic."
Expected headings
"Embryology"
"Dizygotic twins are the most common type of multifetal pregnancy, accounting for approximately 70%. There is significant racial variation in incidence. The overall incidence is increasing due to the use of in vitro fertilisation (IVF)."
"ethnicity (e.g. Nigerian 3)"