Your first trimester prenatal visit at Lehigh Valley Health Network (LVHN) is one of the most important. It may take longer than other visits because your provider will take a full medical history and provide a complete physical exam. After this appointment, plan to see your provider about every four weeks depending on how your pregnancy is developing.

First trimester prenatal care

Your first prenatal visit with your LVHN obstetrics provider is an opportunity for you to ask questions or discuss your concerns about pregnancy. The visit will include a pelvic exam to:

  • Determine the size and position of the uterus
  • Identify the age of the fetus
  • Check the size and structure of the pelvic bone
  • You’ll be scheduled for a safe ultrasound procedure to determine your “estimated date of delivery” (EDD or “due date”).

Early in pregnancy, your provider will test you for Rh factor. This test reveals whether you and your fetus have compatible blood types. If you don’t, we will begin appropriate treatment.

Your LVHN provider may also use these tests to assess your health and the health of your developing baby:

  • Pap smear to detect the presence of abnormal cells
  • Urine test to screen for bacteria, sugar and protein
  • Blood tests to look for infection or lack of iron in the blood (anemia)
  • Ultrasound exam to date your pregnancy
  • Genetic tests to detect health conditions that run in your family or chromosomal abnormalities

What to expect in the first trimester

You may experience the following in early pregnancy:

  • Enlarged breasts: Increased hormones – estrogen and progesterone – cause milk glands in the breast to enlarge in preparation for breastfeeding.
  • Morning sickness: Higher hormone levels may cause feelings of nausea, known as morning sickness.
  • Heartburn and constipation: High levels of progesterone cause muscular contractions of the intestines to slow, resulting in heartburn, constipation and gas.
  • Fatigue: The physical and emotional changes of pregnancy can make you more tired.
  • Blood volume: To keep pace with increasing blood flow to the uterus, your body creates more blood (up to 50 percent more by the end of pregnancy).

Your baby is most vulnerable during the first trimester when developing organs and systems can be damaged by drugs and alcohol. Your LVHN provider can help you adopt a healthy lifestyle that supports pregnancy, including good nutrition in pregnancy.

First trimester growth and development

Every fetus grows at different rates, but your baby will likely meet these milestones:

By the end of four weeks

  • The neural tube (which becomes the brain and spinal cord), the digestive system and the circulatory system begin to form.
  • Eyes and ears begin to develop.
  • Tiny limb buds appear (these will develop into arms and legs).
  • The heart beats.
  • The amniotic sac, a fluid-filled sac that protects the baby from injury, is formed.
  • The placenta and umbilical cord have formed. These exchange nutrients and waste between you and your baby.

By the end of eight weeks

  • The fetus takes on a human shape, though the head is larger than the body.
  • Tooth buds that will become baby teeth develop.
  • Eyes, nose, mouth and ears are more distinct.
  • Fingers and toes form.
  • The fetus moves, but it is too small to be felt.

During weeks 9 to 12

  • External genital organs develop.
  • Fingernails and toenails appear.
  • Eyelids have formed.
  • Arms and legs are fully formed.
  • The organs and body systems are fully formed by the end of 12 weeks, though the fetus cannot yet survive outside the womb.

Care before, during and after pregnancy.

Choose from board-certified obstetricians, maternal fetal medicine specialists, advanced practice clinicians and certified nurse-midwives.

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