A 28-year-old G1P0 woman is diagnosed as having a twin gestation at 15 weeks gestation. Careful examination of the membranes reveals that there is a very thin membrane between the two fetuses. Which of the following statement is most accurate

The ultrasound findings are consistent with monochorionic, diamniotic twins, since there is only a thin membrane between the two gestations. Since a dizygotic gestation always gives rise to a dichorionic diamniotic gestation, this patient must have a monozygotic pregnancy which split at 4 to 8 days after feilization. A monozygotic pregnancy is at greater risk for IUGR, stillbih.