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Pregnancy at 15 to 18 Weeks

Medically reviewed by Last updated on Aug 31, 2022.

What changes are happening in my body?

Now that you are in your second trimester, you have more energy. You may also feel hungrier than usual. You may start to experience other symptoms, such as heartburn or dizziness. You may be gaining about ½ to 1 pound a week, and your pregnancy is beginning to show. You may need to start wearing maternity clothes.

How do I care for myself at this stage of my pregnancy?

Tips for a Healthy Pregnancy
  • Manage heartburn by eating 4 or 5 small meals each day instead of large meals. Avoid spicy foods. Avoid eating right before bedtime.
    Prevent GERD
  • Manage nausea and vomiting. Avoid fatty and spicy foods. Eat small meals throughout the day instead of large meals. Ginger may help to decrease nausea. Ask your healthcare provider about other ways of decreasing nausea and vomiting.
  • Eat a variety of healthy foods. Healthy foods include fruits, vegetables, whole-grain breads, low-fat dairy foods, beans, lean meats, and fish. Drink liquids as directed. Ask how much liquid to drink each day and which liquids are best for you. Limit caffeine to less than 200 milligrams each day. Limit your intake of fish to 2 servings each week. Choose fish low in mercury such as canned light tuna, shrimp, salmon, cod, or tilapia. Do not eat fish high in mercury such as swordfish, tilefish, king mackerel, and shark.
    Healthy Foods
  • Take prenatal vitamins as directed. Your need for certain vitamins and minerals, such as folic acid, increases during pregnancy. Prenatal vitamins provide some of the extra vitamins and minerals you need. Prenatal vitamins may also help to decrease the risk of certain birth defects.
    Sources of Folic Acid
  • Do not smoke. Smoking increases your risk of a miscarriage and other health problems during your pregnancy. Smoking can cause your baby to be born too early or weigh less at birth. Ask your healthcare provider for information if you need help quitting.
  • Do not drink alcohol. Alcohol passes from your body to your baby through the placenta. It can affect your baby's brain development and cause fetal alcohol syndrome (FAS). FAS is a group of conditions that causes mental, behavior, and growth problems.
  • Talk to your healthcare provider before you take any medicines. Many medicines may harm your baby if you take them when you are pregnant. Do not take any medicines, vitamins, herbs, or supplements without first talking to your healthcare provider. Never use illegal or street drugs (such as marijuana or cocaine) while you are pregnant.

What are some safety tips during pregnancy?

  • Avoid hot tubs and saunas. Do not use a hot tub or sauna while you are pregnant, especially during your first trimester. Hot tubs and saunas may raise your baby's temperature and increase the risk of birth defects.
  • Avoid toxoplasmosis. This is an infection caused by eating raw meat or being around infected cat feces. It can cause birth defects, miscarriages, and other problems. Wash your hands after you touch raw meat. Make sure any meat is well-cooked before you eat it. Avoid raw eggs and unpasteurized milk. Use gloves or ask someone else to clean your cat's litter box while you are pregnant.

What changes are happening with my baby?

By 18 weeks, your baby may be about 6 inches long from the top of the head to the rump (baby's bottom). Your baby may weigh about 11 ounces. You may be able to feel your baby's movement at about 18 weeks or later. The first movements may not be that noticeable. They may feel like a fluttering sensation. Your baby also makes sucking movements and can hear certain sounds.

What do I need to know about prenatal care?

During the first 28 weeks of your pregnancy, you will see your healthcare provider once a month. Your healthcare provider will check your blood pressure and weight. You may also need any of the following:

  • A urine test may also be done to check for sugar and protein. These can be signs of gestational diabetes or infection.
  • A blood test may be done to check for anemia (low iron level).
  • Fundal height check is a measurement of your uterus to check your baby's growth. This number is usually the same as the number of weeks that you have been pregnant.
  • An ultrasound may be done to check your baby's development. Your healthcare provider may be able to tell you what your baby's gender is during the ultrasound.
    Pregnancy Ultrasound
  • Your baby's heart rate will be checked.

When should I seek immediate care?

  • You have pain or cramping in your abdomen or low back.
  • You have heavy vaginal bleeding or clotting.
  • You pass material that looks like tissue or large clots. Collect the material and bring it with you.

When should I call my doctor or obstetrician?

  • You cannot keep food or drinks down, and you are losing weight.
  • You have light bleeding.
  • You have chills or a fever.
  • You have vaginal itching, burning, or pain.
  • You have yellow, green, white, or foul-smelling vaginal discharge.
  • You have pain or burning when you urinate, less urine than usual, or pink or bloody urine.
  • You have questions or concerns about your condition or care.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.