Which term refers to the period from conception until birth?

The term that refers to the period from conception until birth is "gestation." This term specifically denotes the developmental phase during which the fertilized egg, now known as an embryo, grows and matures in the womb until it reaches full term, culminating in birth. Gestation encompasses all the physiological changes and growth stages that occur in the fetus as it develops, typically lasting around nine months in humans.

Pregnancy is a broader term that describes the state of carrying a developing fetus, which overlaps with gestation but does not exclusively refer to the developmental processes during that time. Development is a general term that can apply to growth and maturation in various contexts, not specifically tied to the prenatal period. Conception refers specifically to the moment when a sperm fertilizes an egg, marking the beginning of the gestation process, but does not cover the entire duration from conception to birth. Therefore, gestation is the most precise term for the period in question.