High incidence of monozygotic twinning after assisted reproduction is related to genetic information, but not to assisted reproduction technology itself

We propose that the high incidence of MZT in infertility-clinic patients is conditioned by hereditary factors, and good ovarian function only facilitates the expression. The resulting recommendation is that young women with a positive family history and good ovarian function undergo elective single-embryo transfer, and proper counseling is advisable.