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Your Third Trimester of Pregnancy

The third trimester can be physically and emotionally challenging for pregnant women. It brings back some of the toughest symptoms of early pregnancy such as fatigue and the frequent need to pee and introduces new ones like Braxton-Hicks contractions and bad aches and pains. In addition to being uncomfortable, you likely are feeling anxious. Researching and understanding what to expect during this final stage of pregnancy can help alleviate worry and help you prepare.

How Long Is the Third Trimester?

The third trimester spans between 9-13 weeks, starts week 29 and lasts until you give birth around week 40. A baby is considered full term at the end of week 37.

What to Expect During the Third Trimester

At this stage, you’re probably feeling a mix of tiredness, worry, excitement and impatience. You’re still having many of the same discomforts. Except, as your body grows, you’re even more uncomfortable. Take good care of yourself. Your baby is busy putting on her finishing touches and needs you to stay healthy.

Third Trimester Symptoms

Your baby is getting bigger, which puts more stress on your body. During your third trimester, you’re likely feeling lots of aches and pains. You’re beginning to slow down after the energy burst from your second trimester. Fatigue is setting in again and you’re feeling anxiety spike.

During your third trimester, you’ll gain half a pound to 1 pound per week, meaning by the end of your pregnancy, you’ll gain between 25 and 35 pounds.

You may notice the following symptoms as you get closer to delivery:

  • Baby “drops”
  • Baby moves around a lot
  • Belly button pops out
  • Braxton-Hicks contractions (“fake” contractions)
  • Difficulty sleeping
  • Heartburn
  • Hemorrhoids
  • Larger breasts
  • Leaky breasts
  • Lower back and hip pain
  • More frequent need to pee
  • Nipples and areolas darken and are more pronounced
  • Pelvic spread (pregnancy “waddle”)
  • Sciatica (tingling, numbness or shooting pain in lower back, butt and thighs)
  • Shooting pain in your pelvis
  • Shortness of breath
  • Swollen ankles, fingers, or face
  • Tender breasts
  • Trouble sleeping

While you don’t feel it, as you near your due date your cervix becomes dilated and effaced to get ready for delivery. Here’s how to know when you’re in labor.

Call your doctor immediately if you experience:

  • Bleeding at any time
  • Extreme swelling
  • High fever
  • Painful contractions of increasing intensity and frequency
  • Painful or burning urination
  • Rapid weight gain
  • Severe cramping or abdominal pain
  • Sudden decrease in activity by your baby
  • Vomiting

What’s Happening to Baby in the Third Trimester

Babies are considered full term after 37 weeks. Full-term babies are 19 to 21 inches and weigh 6.75 to 10 pounds.

During the third trimester, your baby’s brain development is in overdrive. Her bones harden and she can open and close her eyes. After week 30, your baby puts on 1.5 pounds per week. Around week 36, she moves head-down to get into position for birth. After week 37, her organs can function on their own.

Third Trimester Prenatal Care

You meet more frequently with your doctor during the third trimester - every two weeks until week 35, then weekly until delivery.

At every visit, your doctor collects a urine sample, takes your blood pressure, measures your fundal height, asks about fetal movement (kick counts). Your doctor also conducts a vaginal exam to see if your cervix is dilated (opening) or effaced (thinning). For a successful vaginal birth, your cervix needs to be 10 cm and 100% effaced.

Be sure to talk to your doctor about how you are feeling and any symptoms you’re having. Also, now’s the time to make your birth plan and decide on what kind of pain relief you want during labor and delivery.

Around week 36, your doctor performs a Group B strep test, a bacterium harmful to a baby that has to be treated with antibiotics. Around this same time, your doctor feels your abdomen to see if baby has settled into a head-down position for birth. Most babies who are breech (butt down) naturally turn head-down by 37 weeks.

Third Trimester Checklist

As with the previous trimesters, it’s important to continue to stay healthy. Also, keep moving! Little walks several times during the day can help alleviate pain. You also may need to stop long car trips and airplane flights after 34 weeks in case you go into labor.

In addition, here’s a list of things you may want to do before baby arrives:

  • Develop a birth plan with your doctor
  • Research and decide on pain relief during labor 
  • Schedule your postpartum follow up appointments
  • Go on a tour of Banner Health’s Maternity Ward
  • Pre-register at Banner Health
  • Attend a Banner Health prenatal class to learn about what to expect during labor
  • Take a breastfeeding class at Banner Health
  • Pack your hospital bag
  • Plan your route and transportation to the hospital
  • Pick a pediatrician
  • Decide on circumcision
  • Make a labor playlist
  • Meditate to calm your mind
  • Finalize paperwork for your maternity leave
  • Create a maternity leave plan for your coworkers
  • Make a few freezer meals
  • Spend some time with your partner
  • Download a contraction app timer
  • Check with your insurance to see how to add your baby
  • Check with your insurance to see if they cover a breast pump
  • Install the car seat
  • Make a plan about how to deal with visitors
  • Find a family member or friend who can care for your pets or other children
  • Wash your baby’s new clothes and linens
  • Get your nursery ready
  • Stock up on baby supplies, like diapers, wipes, and baby clothing in different sizes
  • Check that your smoke detectors and carbon monoxide detectors in your home
  • Celebrate your pregnancy with friends and family

Learn more about Banner Health’s pregnancy resources, classes, education materials and support groups.