In fanfiction, their pregnancy could potentially have a big impact on their careers. They might have to take time off, which could set them back in terms of their medical training or research. However, it could also give them new perspectives. For example, Meredith might become more interested in obstetrics after her own pregnancy experience, and Alex could find a new passion for pediatrics, seeing the importance of taking care of children through his own child.
It could also impact their careers in terms of their relationships with colleagues. Some colleagues might be very supportive, while others could be jealous or judgmental. This could create new storylines in the fanfiction. For instance, they might face some discrimination from an old - fashioned doctor who doesn't think they should be parents and doctors at the same time. But they could also prove this doctor wrong by still being excellent at their jobs while raising a family.