noun
natural conception; natural pregnancy
Medical and everyday term for pregnancy achieved without assisted reproductive technology (ART). Often contrasted with 体外受精 (in vitro fertilization) or 人工授精 (artificial insemination).
不妊治療をやめたら、自然妊娠しました。
After stopping fertility treatment, I conceived naturally.
自然妊娠の確率は年齢とともに下がります。
The probability of natural conception decreases with age.
Compound of 自然 (natural) and 妊娠 (pregnancy/conception). A straightforward modern medical term.