Culture is represented in a groupâs: 1  language, 2  decision making, 3  symbols, 4  stories and legends, and. 5  daily work practices.
The third trimester starts at 28 weeks and continues until the birth of your baby. This is the seventh month of your pregnancy and during this time the fetus grows larger and the organs begin to mature.
From 12 weeks to 27 weeks the fetus continues developing and reaches viability. From 27 weeks on the fetus finishes development and prepares for delivery. Here the second trimester begins at 12w 0d and the third at 27w 0d. With this method you take the 40 weeks of gestation and divide into three equal stages. Here the second trimester begins at 13w 3d and the third at 26w 6d. This method is where you take the 38 weeks of post conception development, divide by three, into the three equal trimesters. Here the second trimester begins at 14w 5d and the third at 27w 3d. The length of the trimesters is often a source of confusion. The word trimester means 'three months'.