3 yrs ago my niece went into labor at 22 weeks because of an infection of the amniotic fluid. drs said there wasn't anything they could do because antibiotics would hurt the baby. why not try to stop labor and give antibiotics? i don't understand?

When amniotic fluid is infected likely due to premature rupture, the pregnancy has to be terminated for the mother's safety and there's no chance for fetal survival.

Once there is infection within the amniotic fluid/sack the ability to kill off the invading germ is minimal. Germs fill the amniotic fluid and enter the fetus/fetal blood. Antibiotics cannot be effectively delivered to that space to kill them. It eventually becomes a sack of puss with fetal loss. Without effective removal of the infected fetus, the mother will become septic and die also.