noun
full-term birth; term delivery
Medical term for a birth that occurs at full term (between 37 and 41 weeks of gestation).
正期産で生まれた赤ちゃんは、一般的に体重が安定しています。
Babies born at full term generally have a stable weight.
過期産 means post-term birth (after 42 weeks), contrasting with 正期産 which is the normal term delivery.
Compound of 正期 (seiki, 'full term') and 産 (san, 'birth'). The exact historical derivation is uncertain, but the term is a modern medical coinage.