Your 31-week prenatal appointment is a routine third-trimester checkup that typically takes 15 to 20 minutes. It focuses on monitoring your blood pressure, tracking your baby’s growth, and checking for signs of complications like preeclampsia or preterm labor. Depending on your provider’s schedule, this may also be the visit where you receive the Tdap vaccine.
Vital Signs and Basic Checks
Every third-trimester visit follows a similar pattern. Your provider will weigh you, take your blood pressure, and collect a urine sample. These three quick checks do a lot of heavy lifting: weight gain that’s too fast or too slow can signal nutritional issues or fluid retention, and a blood pressure reading at or above 140/90 mmHg is the traditional threshold for hypertension in pregnancy. If your blood pressure is elevated, your provider will test your urine for excess protein, which together with high blood pressure can point to preeclampsia.
Your provider will also check your hands, feet, and ankles for swelling. Some puffiness is completely normal in the third trimester, but sudden or severe swelling, especially in the face or hands, is one of the things they’re watching for as a possible sign of a blood pressure disorder.
Measuring Your Baby’s Growth
With you lying on your back, your provider will measure the distance from your pubic bone to the top of your uterus with a flexible tape measure. This is called fundal height. At 31 weeks, a measurement between about 29 and 33 centimeters is considered normal, since the general rule between weeks 20 and 36 is that the number in centimeters should be close to the number of weeks, plus or minus two. A measurement that falls outside that range doesn’t necessarily mean something is wrong, but it may prompt an ultrasound to get a more detailed look at your baby’s size and the amount of amniotic fluid.
At this stage, your baby weighs roughly 3.5 to 4 pounds and will gain about half a pound each week from here on out. Your provider won’t weigh the baby directly at this visit unless they order an ultrasound, but the fundal height gives a reliable estimate of whether growth is on track.
Listening to the Heartbeat and Checking Position
Your provider will use a handheld Doppler device to listen to your baby’s heartbeat. A normal fetal heart rate ranges from about 110 to 160 beats per minute. You’ll hear the quick, rhythmic sound yourself, which is one of the more reassuring parts of the visit.
Starting around this point in the third trimester, your provider may also press gently on your abdomen to feel where the baby’s head, back, and bottom are. At 31 weeks, plenty of babies are still breech (bottom or feet down) or lying sideways, and that’s not a concern yet. Most babies settle into a head-down position by 36 weeks. If yours hasn’t flipped by then, your provider will discuss options, which could include a hands-on technique to encourage the baby to turn or planning a cesarean delivery.
The Tdap Vaccine
The CDC recommends the Tdap vaccine (which protects against whooping cough, tetanus, and diphtheria) between weeks 27 and 36 of each pregnancy, with a preference for the earlier part of that window. At 31 weeks, you’re right in the sweet spot. Your body needs about two weeks after the shot to build peak antibody levels, and it takes additional time to pass those antibodies to your baby through the placenta. Getting vaccinated now gives your newborn the best possible protection against whooping cough during those vulnerable first months before they can be vaccinated themselves.
If you received the Tdap during a previous pregnancy, you still need it again this time. Antibody levels decline between pregnancies, so each baby needs a fresh dose.
Topics Your Provider Will Ask About
Expect your provider to ask about a few specific things at this visit. They’ll want to know whether you’ve noticed any contractions, vaginal bleeding, or fluid leaks. At 31 weeks, the goal is to catch any signs of preterm labor early. Symptoms worth mentioning include regular tightening in your belly, a dull low backache that doesn’t go away, pelvic pressure, or any watery or bloody vaginal discharge.
Your provider may also bring up fetal movement. By 31 weeks, you should be familiar with your baby’s activity patterns. If you haven’t already been doing kick counts, this is a good time to start. The basic approach is to pick a time when your baby is usually active, sit or lie down, and count how long it takes to feel 10 movements. Most babies hit that number well within an hour. If it takes longer than two hours to feel 10 movements, that’s worth a call to your provider. The pattern matters more than any single count: a baby who is normally very active and suddenly becomes quiet is more concerning than a baby who has always been on the mellow side.
Early Delivery Planning Conversations
While your due date is still about nine weeks away, your provider may start talking about labor and delivery logistics at this visit or at the next one. Common topics include your preferences for pain management, whether you’ve taken a childbirth preparation class, and any questions you have about what labor will feel like. If you have a specific birth plan in mind, this is a good time to share it so your provider can discuss what’s realistic given your health and your baby’s position.
Some providers also mention Group B Strep testing at this appointment, though the actual test is usually done between weeks 36 and 37. Knowing it’s coming gives you time to read up on what it involves (a simple vaginal and rectal swab) and what a positive result means for your labor.
How Often Visits Happen From Here
At 31 weeks, you’re likely on a schedule of appointments every two weeks. That will shift to weekly visits around week 36. The increasing frequency isn’t because something is expected to go wrong. It’s because the third trimester is when conditions like preeclampsia and gestational diabetes complications are most likely to develop, and catching them early makes a significant difference in outcomes for both you and your baby.