Women lucky enough to live in 1 of the 8 states that mandates insurance coverage of in vitro fertilization (IVF) may be even more lucky than they realize. According to the latest research presented by Yale School of Medicine researchers at this week’s annual American Society for Reproductive Medicine conference, those mom-wannabes are less likely to give birth to multiples. Premature birth is the biggest worry. According to the American College of Obstetricians and Gynecologists, 50 percent of twins and 90 percent of triplets arrive early, which puts them at higher risk of everything from birth defects to developmental delays. When it comes to the link between IVF and multiples, scientists suspect the devil’s in the price tag—at nearly $10,000 a pop, IVF is not for the feint of wallet. “These results suggest that when couples bear the expense of IVF, physicians might feel pressure to transfer more embryos,” says Dr. Pasquale Patrizio, director of the Yale Fertility Center. This news make you want to move? States that make insurance companies pay up include Arkansas, Connecticut, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, and Rhode Island.