Translation guide
A physical or biochemical abnormality present at birth. In Japanese, the most common and neutral term is 先天性異常 (せんてんせいいじょう). Other terms vary by formality and context.
There are various causes of birth defects.
Slightly shorter variant, also common in medical contexts.
Early detection of birth defects is important.
Literally 'congenital disease', often used interchangeably with 先天性異常.
This birth defect is hereditary.
Using a more formal or academic term, often in written reports.
Talking about a birth defect in a casual conversation.
The English word 'defect' can sound harsh. Japanese terms like 異常 (abnormality) or 障害 (disability) are more common and less stigmatizing in medical contexts. 欠陥 (defect) is rarely used for people.
先天性異常 is a broad term covering any congenital anomaly, including functional disorders. 先天奇形 specifically refers to structural malformations (e.g., cleft lip, heart defects). Use 先天奇形 only when the defect is morphological.
He had surgery for a birth defect.
I have a birth defect and go to the hospital regularly.