Definition: The beginning third of a human PREGNANCY, from the first day of the last normal menstrual period (MENSTRUATION) through the completion of 14 weeks (98 days) of gestation.
human only; check tags HUMANS & FEMALE & PREGNANCY; DF: PREGN TRIMESTER FIRST
Other names Trimester, First; Pregnancy, First Trimester; Early Placental Phase; Pregnancy Trimesters, First; Pregnancies, First Trimester; Placental Phases, Early; Trimesters, First; Placental Phase, Early; Phases, Early Placental; Phase, Early Placental; First Trimesters; First Trimester Pregnancy; First Trimester Pregnancies; First Trimester; First Pregnancy Trimesters; First Pregnancy Trimester; Early Placental Phases
