First trimester pregnancy: What to expect

First trimester pregnancy can be overwhelming. Understand the changes you might experience and how to take care of yourself during this exciting time.

By Mayo Clinic Staff

The first trimester of pregnancy is marked by an invisible — yet amazing — transformation. And it happens quickly. Hormones trigger your body to begin nourishing the baby even before tests and a physical exam can confirm the pregnancy.

Knowing what physical and emotional changes to expect during the first trimester can help you face the months ahead with confidence.

Your body

While your first sign of pregnancy might have been a missed period, you can expect several other physical changes in the coming weeks, including:

  • Tender, swollen breasts. Soon after conception, hormonal changes might make your breasts sensitive or sore. The discomfort will likely decrease after a few weeks as your body adjusts to hormonal changes.
  • Nausea with or without vomiting. Morning sickness, which can strike at any time of the day or night, often begins one month after you become pregnant. This might be due to rising hormone levels. To help relieve nausea, avoid having an empty stomach. Eat slowly and in small amounts every one to two hours. Choose foods that are low in fat. Avoid foods or smells that make your nausea worse. Drink plenty of fluids. Foods containing ginger might help. Motion sickness bands, acupuncture or hypnosis might offer relief — but get the OK from your health care provider first. Contact your health care provider if your nausea and vomiting is severe.
  • Increased urination. You might find yourself urinating more often than usual. The amount of blood in your body increases during pregnancy, causing your kidneys to process extra fluid that ends up in your bladder.
  • Fatigue. During early pregnancy, levels of the hormone progesterone soar — which can put you to sleep. Rest as much as you can. A healthy diet and exercise might help boost your energy.
  • Food aversions. When you're pregnant, you might become more sensitive to certain odors and your sense of taste might change. Like most other symptoms of pregnancy, food preferences can be chalked up to hormonal changes.
  • Heartburn. Pregnancy hormones relaxing the valve between your stomach and esophagus can allow stomach acid to leak into your esophagus, causing heartburn. To prevent heartburn, eat small, frequent meals and avoid fried foods, citrus fruits, chocolate, and spicy or fried foods.
  • Constipation. High levels of the hormone progesterone can slow the movement of food through your digestive system, causing constipation. Iron supplements can add to the problem. To prevent or relieve constipation, include plenty of fiber in your diet and drink lots of fluids, especially water and prune or other fruit juices. Regular physical activity also helps.
April 14, 2017 See more In-depth