Third-Trimester Prenatal Visits

After eight months of pregnancy, you’re already well acquainted with your doctor. You’ve been poked, prodded, scanned, and then poked again. If your pregnancy has been progressing normally, you’ve probably been seeing your doctor once or twice each month.

But now that you’re in the home stretch, you’ll be spending even more time in the doctor’s office. Starting at about week 36, your doctor will probably want to see you once a week. These visits give your doctor an important opportunity to head off any last-minute problems before they can complicate delivery. Doctors have different styles, and women have different needs, but here’s what you can expect from your last prenatal exams.

Covering the basics

Just like at every other prenatal appointment, your doctor will check your blood pressure and your weight. These are two vital signs during pregnancy, and they become especially important late in the last month. A sudden rise in blood pressure or rapid weight gain may be a sign of preeclampsia, a serious condition that requires immediate treatment.

Your doctor will also check your hands and feet for excess swelling, another possible sign of preeclampsia. And, just like at previous visits, he or she will listen to the baby’s heartbeat and measure the size of your belly to make sure your baby is growing on pace.

Urine test

A small sample of urine can say a lot about your pregnancy. Your doctor will test for two things: protein, which can be a sign of preeclampsia, and excess sugar, which can be a sign of gestational diabetes.

Strep test

If you haven’t had one already, you’ll need a test to see if you’re carrying group B streptococcus, a common bacterium that could potentially harm your baby if it spreads during delivery. Your doctor will check for the germ by gently swabbing your vagina and rectum. If you have the bacterium, you may need antibiotics during labor.

Measuring your cervix

Your doctor may want to perform a vaginal exam to see if your cervix is getting ready for labor. Although it is often not necessary, this can be important if your doctor is looking for the right time to induce labor.

There are two main measurements: dilation (how far your cervix has opened) and effacement (how much your cervix has thinned).

When your baby is ready to come out through the vagina, you’ll be dilated 10 centimeters and 100 percent effaced. For now, it may be more like 2 or 3 cm and 30 percent, or you may not have any dilation or effacement at all. These measurements are far from perfect predictors of your readiness to give birth. You can be partially dilated and effaced for weeks before going into labor, but you could also go into labor without any dilation or effacement. Your doctor is likely to skip the dilation and effacement measurements if there’s no plan to induce labor.

By now, your baby should be lying head down. Your doctor can check your baby’s position by feeling your abdomen for identifiable body parts such as the head and the rump. He or she may also perform a vaginal exam to feel for your baby’s head just above your pubic bone.

If your baby’s position still isn’t clear, your doctor may perform an ultrasound scan to settle the question. If your baby happens to be head up — also known as the breech position — your doctor may be able to turn him over by pushing on your abdomen. If your baby remains in the breech position, you may have to have a cesarean section. It’s possible to deliver a breech baby vaginally, but only in special situations.

Preparing for the big day

These final checkups give you a great opportunity to ask questions about labor and delivery. By now, your doctor should have a clear idea about how things should go. Discuss your birth plan, ask for his or her advice, and talk about what you should do when labor starts. This is really going to happen. And you need to be prepared.


Mayo Clinic. Third trimester prenatal care. June 2010.

Lucile Packard Children’s Hospital at Stanford. Pregnancy & Childbirth: The third trimester.

March of Dimes. Prenatal Care. 2010.

Pregnancy-Induced Hypertension. American Academy of Family Physicians. 12/09

Breech Births. American Pregnancy Association.

Prenatal Care Guideline Recommendations. Texas Childrens Hospital.

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