While no one would say it’s all downhill from here (there’s labor after all, as well as the aches and pains of late pregnancy), for many women the second trimester feels like the “easy” part of pregnancy. Fear of miscarriage subsides, nausea abates, and energy surges — all in all, there’s less to be worried about.
Of course, prenatal visits are still essential, and for most moms, prenatal exams will still occur monthly. That’s because a number of tests that can give you key information about your baby’s health are possible at this stage. (And tell whether you’re carrying a boy or a girl, should you choose to find out!)
Here is what your second-trimester prenatal visits will cover:
Your baby’s size and weight
At each visit, your doctor or midwife will measure you from the top of your uterus to your pubic bone. This is called the fundal height and, measured in centimeters, it corresponds approximately to the number of weeks of pregnancy. (For example, 24 centimeters equals 24 weeks.) Using this measurement, your practitioner can tell if your baby is growing well and can more accurately determine your due date.
Towards the end of this trimester, your doctor or midwife will begin checking the baby’s position to see if the head is pointing downward, the optimal position for birth. Typically, an ultrasound will be done at about 18 to 20 weeks. Even if your baby isn’t positioned headfirst at this point, there is still time for her to change position before delivery.
Your overall health
If you’re wondering why your practitioner always examines your hands and feet, it’s to check for swelling, also called edema. Although some swelling is normal during pregnancy, persistent, obvious swelling can be a sign of preeclampsia, a potentially serious condition for both you and your baby.
Although preeclampsia is generally more common in the third trimester, be on the watch now for this and other indications: severe headaches, changes in vision, dizziness, severe stomach pain, unusually rapid weight gain (a pound or more a day), and an increase in blood pressure or protein in the urine that may show up in test results from your prenatal checkups.
Toward the end of the second trimester, your doctor may administer a blood test called a glucose challenge test, which is used to check for gestational diabetes. This is a form of diabetes that develops in roughly 3 to 8 percent of pregnant women. Usually it goes away after your baby is born, but it may increase the likelihood that you’ll develop diabetes later in life.
Your doctor may suggest that you be tested for anemia as well. If your blood type is Rh negative (which means you don’t carry the Rh protein on the surface of your blood cells) and your partner is Rh positive (which means his blood cells do carry the Rh protein) your doctor will probably recommend a test to see if you have Rh antibodies. These antibodies may attack your baby’s blood cells if her blood is Rh positive like her father’s. If your body is producing Rh antibodies, your doctor will monitor you to make sure they don’t cause a problem. If you are Rh negative, your doctor will probably recommend an injection of a drug called Rhogam to keep antibodies from forming.
The doctor may also ask you about varicose veins, hemorrhoids, and other discomforts of pregnancy to monitor your overall condition.
Your baby’s health
Depending on your age and risk factors, there are a number of tests your doctor may recommend that can help determine if your baby has a genetic disorder or other birth defect. (The risk of birth defects increases if you are 35 or older.)
The triple screen or quadruple screen test checks for Down syndrome and defects in the neural tube — the structure that will develop into your baby’s brain and spinal column and is usually performed between 15 and 18 weeks. Amniocentesis — which will be offered to you if your triple or quadruple screen test or other non-invasive screening raises concerns — is usually performed somewhere around 18 weeks.
Usually between the 18th and 20th week, your doctor or midwife will order an ultrasound to determine the baby’s position and check for detectable birth defects such as spina bifida. This is sometimes your first opportunity to find out if you are having a boy or a girl, if you want to know.
If you haven’t heard your baby’s heartbeat already (some women get to hear it as early as 10 weeks), you’re in for a thrill. The doctor will listen for it at every visit after 10 weeks, so there are usually plenty of chances to hear it besides at the time of your ultrasound. Your doctor or midwife will use a handheld ultrasound instrument called a Doppler to listen for your baby’s heartbeat through your belly.
Many factors can influence how soon the heartbeat is audible, including the baby’s position, how much you weigh, and how much noise there is in the room. If you don’t hear it the first time, don’t worry — sometime during this trimester, you will.
Planning for the future
During your second-trimester visits, you may also want to ask your doctor or midwife about childbirth education classes. These are often offered through the hospital where you plan to deliver, but if not, you may wish to sign up for a class privately. Some hospitals and practices also offer CPR and breastfeeding classes that you can plan for in advance. These classes book up early, so it’s good to plan ahead.
National Women’s Health Information Center. The Second Trimester. http://www.4woman.gov/Pregnancy/second.cfm
Mayo Clinic. Second Trimester Prenatal Care. June 2010. http://www.mayoclinic.com/health/prenatal-care/PR00093
What to Expect When You’re Expecting. Heidi Murkoff, Arlene Eisenberg & Sandee Hathaway. Workman Publishing.
American Academy of Family. Pregnancy-induced Hypertension. 12/09
National Diabetes Information Clearinghouse. What I Need to Know About Gestational Diabetes.
University of Michigan Health System. RH Factor and Pregnancy. http://www.med.umich.edu/obgyn/smartmoms/pregnancy/pretest/rhfactor.htm
March of Dimes. Gestational Diabetes. November 2008
March of Dimes. High Blood Pressure and Preeclampsia 2007
March of Dimes. Your First Tests.
Nemours Foundation. 10 things that Might Surprise You About Being Pregnant. June 2008
March of Dimes. Maternal Blood Screening for Down Syndrome and Neural Tube Defects. June 2004.
Graves, J.C. et al. Maternal Serum Triple Analyte Screening in Pregnancy. American Family Physician. 65:915-920,922. http://www.aafp.org/afp/20020301/915.html
American Pregnancy Association. Ultrasound: Sonogram. http://www.americanpregnancy.org/prenataltesting/ultrasound.html
U.S. Department of Health and Human Services. National Guideline Clearinghouse. Routine prenatal care. http://www.guideline.gov/
Palo Alto Medical Foundation. Your Second Trimester.