Mayo Clinic Health Library

Prenatal care: 2nd trimester visits

Updated: 08-04-2012

Prenatal care is an important part of a healthy pregnancy, starting as soon as you think you're pregnant. As your pregnancy progresses, you'll continue to visit your health care provider regularly — probably once a month throughout the second trimester, or weeks 14 to 27 of pregnancy.

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

Review the basics

Your health care provider will check your blood pressure and weight at every visit. Mention any signs or symptoms you've been experiencing.

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

  • Track your baby's growth. By measuring your abdomen from the top of your uterus to your pubic bone, 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 or occasionally a modified stethoscope. The Doppler instrument detects motion and conveys it as sound, which allows you to "hear" the baby's movement.
  • 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.

Expect routine lab tests

You might need blood tests to check for low iron levels or gestational diabetes, a type of diabetes that can develop during pregnancy.

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.

A urine sample might be tested for signs of a bladder, urinary tract or kidney infection.

Consider prenatal testing

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

  • Blood tests. Blood tests might be done to screen for developmental 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. An ultrasound can help your health care provider evaluate your baby's growth and development. It also gives you an exciting glimpse of your baby.
  • 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.

Keep your health care provider informed

The second trimester often brings a renewed sense of well-being. Still, 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.