Most common twins after assisted reproduction:
Most common twins after assisted reproduction are dizygotic twins. For increasing the success of IVF and the expenses involved, it's a norm to transfer 2-3 embryos of day 3 or 1-2 embryos of Day 5. For women lesser than 35 years, the implantation rate is better and hence these are the ones who have more multiple pregnancies.
Monozygotic
Acardiac twin
Dizygotic twin
Conjoined twin
Twin Pregnancy, Molar Pregnancy, Gestational Trophoblastic disease and contraception in special situations (Sour Grapes!)