What are the effects of general anesthesia on a fetus?

The same as you: The fetus will get most of the same drugs and effects as the mother (there are some drugs that do not cross the placenta)--but for the most part these drugs will leave the fetus quickly once delivered from the uterus--it really all depends on how long it takes the surgeon/ob to deliver the baby by c-section. Most of the time the apgars are no different than from a vaginal/epidural delivery.

Most anesthetics : Effect the fetus similarly to the way they effect the mom. If given prior to delivery, the newborn may be sleepy and require support. Some medications, like benzodiazepines, should be avoided during part of the pregnancy.

Variable: General anesthesia has been known to precipitate delivery resulting in premature delivery or spontaneous abortion. This is the reason that one's pregnancy status must be declared if getting xrays or contemplating surgery. If surgery is needed emergently or urgently then the risks have to be seriously weighed by patient and family.

Decrease blood flow: Main concern in anesthesia is a decrease in blood pressure in the mother that can lead to a decrease of blood flow in the placenta. This can be easily treated and managed by your anesthesiologist. There is also a concern that anesthesia and surgery might induce early labor. Again this can be monitored and treated. I hope all goes well.