Conjoined twins in a spontaneous trichorionic quadruplet pregnancy: a case report.

Background: Multifetal pregnancies are high-risk pregnancies. Coexistence of conjoint twins with multifetal pregnancies further increases the risk factor, which is already considerably high with multiple births. Assisted reproductive techniques lead to an increase in multifetal pregnancies, especially monozygotic pregnancies, which in turn lead to an increase in the rate of conjoined twins.