BERLIN — Embryos created during in vitro fertilization can be screened for genetic defects before being implanted in the womb, a German high court said in a landmark ruling Tuesday. The Federal Supreme Court in Leipzig ruled in support of a Berlin gynecologist who had carried out screening on embryos for three different couples and implanted only those that were healthy. The embryos with hereditary genetic defects were left to die off. The high court's ruling upheld a decision by a Berlin state court that the doctor's action did not violate German laws for the protection of embryos. The 47-year-old doctor, who was not identified by the court, brought the case to court himself in 2006 to clarify the legal situation. He was first acquitted by a regional court in Berlin, but the city's state prosecutor appealed.