PITTSBURGH (AP) _ The wife of a British diplomat said she expects to leave Pittsburgh this week for El Salvador with the homeless, month-old boy she brought here for medical care after he was rescued from a San Salvador garbage dump.

''There's no question of him staying. His legal situation in El Salvador has to be sorted out. He hasn't even got a birth certificate,'' said Dora Ridgway, wife of British charges d'affaires in the Salvadoran capital.

But Mrs. Ridgway said she does not intend to relinquish the boy, whom she has named Benjamin Paz.

''I will certainly not hand him over to the state health authorities, not because they'll ill treat him but because they don't have the funds to handle these kids. They're struggling with so many children,'' she said Wednesday.

She said she will seek permission to care for the boy until he can be placed with an adoptive family. Mrs. Ridgway said she does not intend to try to adopt him.

Salvadoran officials may approve her request because they cooperated in letting her take the baby to Pittsburgh for medical testing, necessary to qualify him for international adoption, she said.

Mrs. Ridgway learned of the baby through news coverage of his story. He had been burned by the sun and bitten by insects in the dump.

While some of the test results may not be available for several weeks, the baby appears to be in perfect health, she said.

''He's a miracle baby,'' Mrs. Ridgway said.

West Penn Hospital received several calls and Mrs. Ridgway said she received others from people interested in adopting the boy.