What to Expect During Your Third Trimester: Weeks 27-40

Whether you’ve just begun your third trimester, or are quickly preparing for the birth of your baby, it seems that your pregnancy continues to have surprises for you. Many women are relieved to get to the third trimester, knowing they only have a number of weeks before meeting their bundle of joy. Others may feel discomforts and anxieties rise up as they approach delivery. We’ll walk through changes in your baby’s body and yours, nutrition and exercise, and what to expect of prenatal care. The presented information comes from the book Your Pregnancy and Childbirth written by the American College of Obstetricians and Gynecologists.

Physical Changes:

Baby’s Body

The third trimester of pregnancy brings continued development and refinement of many bodily systems and processes. In the coming months, your baby’s skin will gain more pigmentation caused by melanin production and will lose lanugo (fine hairs which regulate body temperature). This is because your baby’s body begins to regulate his or her own body temperature instead of relying on the amniotic fluid. Your baby prepares for birth by moving into a head down position and the final lung, brain and nervous system development are all in play.

For more information on the second trimester, you can watch this video.

Your Body

Unfortunately, as the second trimester comes to an end, some of the initial discomforts of the first trimester can make a reappearance. Here are some typical symptoms and discomforts in the third trimester:

• Lower Back Pain- there are a few causes of back pain:
  • Relaxin, a hormone which helps loosen your ligaments for labor and delivery, can also relax the muscles that help support weight.
  • Sciatica is a condition in which pressure from your uterus on your sciatic nerve can cause back and pelvic pain which can also impact your legs.
• Pelvic Bone Pain- caused by pressure on your pelvic bones
• Constipation
• Hemorrhoids
• Braxton Hicks (also known as practice contractions)
• Shortness of breath
• Varicose Veins
• Leg Swelling or Cramping
• Frequent Urination

Nutrition and Exercise:

Diet

Some important dietary considerations for this trimester include:

• Focus on water and fiber
  • Relieves constipation
  • Ensures appropriate amounts of amniotic fluid
  • Aids in digestion
  • Circulates nutrients efficiently
• Try to include calcium for healthy bone development in baby
• Utilize Vitamin C to aid both you and your baby’s immune systems

Exercise

This trimester is about preparing your body for labor. Exercise should help you to strengthen muscle but also focus on relaxation techniques. Swimming continues to be a good, low-impact exercise which helps get your heart rate up while not straining your body too much.

A helpful hint: Contraction pain is simply muscle fatigue. Similar to how your legs burn when doing a long wall sit, your abdomen muscles get tired from contracting in labor. If you can try an exercise like a wall sit and breathe through the burn in your legs, this can be good practice for breathing through labor contractions.

For any labor preparation, you can try exercises like this: Prenatal Workouts.

Prenatal Care:

In addition to your regular prenatal appointments, the following tests, screens and vaccines may be administered:

• Glucose Test: From 24-28 weeks, your doctor will test how your body processes glucose. This rules out the possibility of gestational diabetes.
• RH Antibody Test: This tests the compatibility of your blood to your baby’s blood. If you test rh negative, you may be given an immunoglobulin injection which ensures that your body doesn’t create antibodies to attack your baby.
• TDAP vaccine: This vaccine helps to prevent whooping cough, tetanus, and diphtheria and is usually given to pregnant women from 27-36 weeks.
• Vaginal Exam: This may be done to check on the progress of your cervix. Your medical provider will discuss if your cervix is dilated or thinned out at all and what this may mean for how soon your labor may occur.
• Group B Streptococci Screening: This screening involves taking a sample of vaginal discharge to test for a natural bacteria which is harmless to adults but can cause issues with your baby when passing through the birth canal. If you test positive, your doctor will provide antibiotics during your labor for the health of your baby.

Special Concerns:

Along with your routine check-ups during pregnancy, your healthcare provider may also address:

• Preterm Labor: Signs that you may be going into labor too early include:
  • Changes in vaginal discharge (increased discharge, which can be watery or bloody)
  • Pelvic pressure
  • Cramping
  • Backaches
  • Contractions
  • Breaking of your water
• Vaginal Bleeding: can be indicative of issues with your placenta
• Amniotic Fluid: having too much or too little amniotic fluid can cause issues in your pregnancy. This may be monitored as you approach delivery.
• Pre-eclampsia: If high blood pressure is detected, your medical provider may suggest an at-home blood pressure cuff or medication if your readings don’t improve.
• Breech Presentation: instead of your baby presenting head down and ready for a vaginal delivery, babies that are breech present with their buttocks or feet down. If your baby doesn’t naturally turn head-down, your medical provider may discuss options to flip your baby or consider a Cesarean section.

*For any questions regarding these special considerations, please talk to your healthcare provider.

Other Considerations:

The third trimester is a great time to discuss your preferences for labor and delivery as well as your plans for baby after he or she is born. Below are just a few things to consider to make life after delivery run more smoothly:

Birth Plan: This is a document that you can bring to the hospital and share with any staff about your desires and preferences for your birth experience. This isn’t required at all but can be a helpful tool to express your goals before you’re in the action of labor.

Packing List: Along with the urge to prepare your house for your newborn, packing a hospital bag can be a way to relieve stress and feel ready to greet your baby! Know that the hospital will have much of what you will need, but always feel free to bring what’s going to make your stay more comfortable.