He declined further comment because, he said, his own investigation was not yet complete. He said Dr. Michael Baden, a forensic pathologist in New York, had conducted a separate autopsy on the baby's body at the request of the Drexler family. In addition, he said, a Pennsylvania psychiatrist, Dr. Robert Sadoff, had examined Miss Drexler. Mr. Secare said he is awaiting both reports.

Dr. Baden said in an interview later today that ''the autopsy findings are ambiguous as to whether the baby was alive, because of all the resuscitation that was performed.''

The resuscitation efforts caused changes in the baby's body, he said, and the birth process might have caused additional changes. ''It's a very difficult type of death to determine, whether a baby was born alive or not,'' Dr. Baden said.

Miss Drexler, an only child, arrived home with her parents shortly before 4 P.M. A crowd of reporters, some with television cameras, on the otherwise quiet street of neat ranch houses called out to her. But Miss Drexler, wearing a sun dress and dark glasses, merely threw her hands in the air, then went inside, bending down to pet her dog on the way.

At a news conference this morning, Mr. Kaye said Dr. Peacock was satisfied that the baby was alive and breathing after the birth because Dr. Peacock had found air in the baby's lungs and intestines.

''The doctor says this is a very significant finding, amongst others,'' Mr. Kaye said of the air in the intestines. The Prosecutor said the medical findings were critical to the state's case, because investigators had not found any witnesses who saw the birth, heard any screams from Miss Drexler or cries from the baby, or saw who placed the bag containing the baby in the bathroom's trash receptacle nine feet from the stall where the birth occurred.

Mr. Kaye said he was convinced that only Miss Drexler knew of her pregnancy. He said the baby was born at full term, without any congenital defects or deformities.