As for magic and tech, I agree, but no amount of magic or tech short of a surrogate or or an artificial incubation womb is going to make a pregnancy a "zero deal let's just continue as before" experience at any lifestyle level much less a low lifestyle as defined in SR.
Mind, as its 2071, I kinda wonder where artifical uteri are. I mean, good god, at the upper end of the richness scale they have rejuvenation treatments that make one practically immortal! And yet nobody thought of such an obviously useful medical appliance like artficial uteri?
That could make for an interesting run in itself. Runner gets pregnant, gets the team to help her steal an artificial womb to tube her baby in. Then you have to find a street doc to hold it for you, one you can REALLY trust.
As to other previous comments that women outside the industrialized middle class can and do lead active, even dangerous lives while pregnant: Sure, and a desperate enough Shadowrunner can do it, too. Any character sheet modifications aside, though, it still won't be easy. Is the team ok with having a pregnant person along with them in a firefight and risking the baby? How about the Fixer who calls up the talent in the first place? How's Mr. J going to react to your maternity armor? I guess the flip side of that is that corp security will do its best to disable rather than kill a pregnant mother. All of these are generalizations, of course. There are surely plenty of people in the shadows who are callous enough to say "your baby, your risk". These are the kind of things that should be made clear in advance. Players have no way of knowing how Shadowrun society differs from their own except the books and the GM. Its only fair to fill them in on things their characters would know.
As a GM, though, I do not want to be the one to run the angst-ridden scene where momma gets shot up, calls Doc Wagon for resuscitation and finds out the baby didn't make it. Maybe Dumpshock can do a little three fold flyer called "so you're pregnant in the shadows" to let mothers to be know what to expect.
Once the baby is born, of course, the character has a new Dependant. So that's easy enough.