I was 12 wk preg. fetus had cystic hygroma&above normal n.t&generalized edema, my dr. decided abortion, was it the right decision?

Trust your doctor: at any rate that's a complex decision to make, from what you wrote it seems that the fetus had multiple anomalies which would be incompatible with life, hope you would have a healthy pregnancy later, good luck

12 wks fetal hydrops: That early in pregnancy, edema is hydrops, generalized; an increased nuchal translucency will be seen, which later in pregnancy may turn into a cystic hygroma, unless septation was already present--as seen in severely affected 45X (Turner syndrome) fetuses. Many other potential causes, but prognosis of hydrops this early is dismal. An amniocentesis prior to abortion allows chromosomal analysis.