The Three Trimesters Of Pregnancy- Learn All About Them A pregnancy is separated into three trimesters: first, second, and third trimesters. A trimester lasts 12 to 14 weeks, but a full-term pregnancy lasts around 40 weeks from the first day of a woman's last menstruation. The fetus will reach particular developmental milestones in each trimester. To learn more, see our blog post on first trimester of pregnancy. https://www.thevoiceofwoman.com/the-three-trimesters-of-pregnancy-know-it-all #pregnancy #trimesters #menstruation #milestones #blog #woman #blogwebsite #Business #Health #thevoiceofwoman