Yes, you may be able to use a Pilates reformer while pregnant—but be sure to talk to your primary care provider before doing so (especially if you’ve never used one before!). And depending on how far along you are in your pregnancy, there may be some modifications you want to consider as you exercise. “We suggest—after the first trimester or at 16 weeks—that women use a wedge to support the upper body when lying down,” Bonney says. “We can also switch some of the exercises to be side-lying instead of lying flat.” She notes that these modifications can make exercises safer and more comfortable for pregnant women. But again, be sure to speak with your primary care provider before working out while pregnant—especially if you’re starting a new routine.