During the second trimester, prenatal care includes routine lab tests and measurements of your baby's growth. You might consider prenatal testing, too.

By Mayo Clinic Staff

The goal of prenatal care is to ensure that you and your baby remain healthy during your entire pregnancy. Prenatal care should start as soon as you think you're pregnant. Your health care provider will ask you to schedule prenatal care appointments about every four weeks throughout the second trimester.

Here's what to expect at your second trimester prenatal appointments.

Your health care provider will check your blood pressure and weight at every visit. Share any concerns you might have.

Then it's time for your baby to take center stage. Your health care provider will:

  • Track your baby's growth. By measuring the distance from the pubic bone to the top of your uterus, your health care provider can gauge your baby's growth. This measurement in centimeters often equals the number of weeks of your pregnancy to date.
  • Listen to your baby's heartbeat. At second trimester visits, you might listen to your baby's heartbeat using a Doppler instrument. The Doppler instrument detects motion and conveys it as sound, which allows you to "hear" the baby's heartbeat.
  • Assess fetal movement. Tell your health care provider when you begin noticing flutters or kicks. This usually happens by about 20 weeks — or perhaps earlier if you've been pregnant before.

During the second trimester, you might be offered various prenatal screenings or tests:

  • Genetic tests. Blood tests might be offered to screen for genetic or chromosomal conditions, such as spina bifida or Down syndrome.
  • Fetal ultrasound. Fetal ultrasound is an imaging technique that uses high-frequency sound waves to produce images of a baby in the uterus. A detailed ultrasound can help your health care provider evaluate fetal anatomy. Fetal ultrasound also might give you an opportunity to find out the baby's sex.
  • Blood tests. Blood tests will be offered to check your blood count and iron levels, screen for a type of diabetes that can develop during pregnancy (gestational diabetes), and check for some infections. If you have Rh negative blood — an inherited trait that refers to a specific protein found on the surface of red blood cells — you might need a blood test to check for Rh antibodies. These antibodies can develop if your baby has Rh positive blood and your Rh negative blood mixes with your baby's blood. Without treatment, the antibodies could cross the placenta and attack the baby's red blood cells — particularly in a subsequent pregnancy with an Rh positive baby.
  • Urine tests. A urine sample might be tested for the presence of protein or signs of infection.
  • Diagnostic tests. If the results of a blood test or ultrasound are worrisome or your history suggests high risk, your health care provider might recommend a more invasive diagnostic test — such as amniocentesis. During amniocentesis, a sample of amniotic fluid — the fluid that surrounds and protects a baby during pregnancy — is removed from the uterus for testing.

The second trimester often brings a renewed sense of well-being. Morning sickness typically begins to dissipate. You begin to feel the baby move. Your belly becomes more noticeable. There's a lot happening.

Tell your health care provider what's on your mind, even if it seems silly or unimportant. Nothing is too trivial when it comes to your health — or your baby's health.

July 22, 2015