The cautious answer is that it’s likely best to opt out of Subway while you’re pregnant.
The main reason boils down to deli meat. Unfortunately, this easy protein isn’t deemed safe for consumption during pregnancy unless it’s heated until it's steaming, which kills off any harmful bacteria. Since most Subway menu items involve deli meats and ingredients that are sitting out at room temperature for longer periods of time, there’s a greater risk of foodborne illness.
Although you could likely get away with a steaming hot Subway sandwich from time to time, the less risky option is to make your own sandwiches or wraps at home. Using leftover cooked protein and veggies that you can wash and prepare yourself is a more pregnancy-friendly option that still offers a convenient and tasty meal.