The First Trimester (First 12 Weeks) The first trimester is a time of profound changes inside your body, and you’ll experience these changes in your own individual way. The first trimester may bring increased energy and a sense of well–being; yet other women may feel increasingly tired and emotional; still others don’t notice many changes until much later in pregnancy. Although the physical changes of early pregnancy may make you uncomfortable, they don’t endanger your health or the health of your baby. Each pregnancy, of course, is unique, and you may experience many, some or none of the changes and symptoms described here.
Nausea and Vomiting Nausea and vomiting in early pregnancy may be due to hormone changes produced by the placenta and the fetus. Changes in your gastro–intestinal system may also play a role–the stomach empties somewhat more slowly under the influence of the hormones of pregnancy. Nausea and vomiting may also be aggravated by emotional stress and fatigue.
Even though it is commonly called “Morning sickness”, the nausea and vomiting in early pregnancy can occur at any time of day. It can be more severe in a first pregnancy, in young women and in women carrying multiple fetuses. Usually, it begins at four to eight weeks of gestation and subsides by 14 to 16 weeks. Some women have nausea and vomiting beyond the first trimester, and a few even throughout their entire pregnancy.
In rare instances, nausea and vomiting may be so severe that a pregnant woman cannot maintain proper nutrition and fluids or gain enough weight. This condition is known as hyperemesis gravid arum. Eating smaller meals more frequently throughout the day often helps alleviate nausea. Drinking less fluid with meals may also provide relief. The idea behind these measures is to avoid having your stomach completely empty or completely full, either of which can make nausea worse.
Breast Tenderness The increased production of the hormones estrogen and progesterone is the primary reason for the changes in a pregnant woman’s breasts. By a few weeks of gestation, you may notice tingling sensations in your breasts, and they may feel heavy, tender and sore.
Weight Gain Although you’ll probably gain about 25 to 30 pounds (11 to 14 kilograms) during the course of your pregnancy, you’ll put on only a small percentage of this amount during the first trimester. A normal weight gain during the first trimester is only about 2 pounds (about 1 kilogram).