When does the third trimester start?
The third trimester starts around week 28, approximately 26 weeks after conception. It spans about 13 weeks (pregnancy months seven through nine) and ends on the day of your baby’s arrival! Timelines can vary from baby to baby, and while your doctor can give you a good idea of when to expect your little one, don’t be surprised if your baby decides to run on their own schedule!
Growth of baby in the third trimester
There’s a lot of growth and development going on beneath that bump that may seem to be expanding endlessly. Hang in there. You’re almost at the finish line!
Pregnancy weeks 28-31
- The 12-week-to-birth countdown starts, and your baby is about the size of a head of iceberg lettuce.
- Their eyes are open, and they can blink.
- Your baby is getting crowded in there. You may feel fewer but stronger movements.
- Their lungs are just about fully developed! Your baby can cough, suck, and hiccup.
- Your baby’s hands are formed, and those tiny fingers that’ll soon be curled around yours even have fingernails.
- The soft hair covering their body is shedding as they develop fat deposits.
- The bone marrow has developed so your baby can produce oxygen-carrying red blood cells.
Pregnancy weeks 32-36
- You may feel some tough kicks from your sweet little wiggle worm.
- Your baby is on the move and should be transitioning into the “birth-ready” position. This is when they face towards your back with their head down and chin tucked to their chest.
- Your baby’s immune system is still developing, but they're absorbing germ-fighting antibodies from you to help protect them after birth.
- The five senses, sight, sound, smell, taste, and touch, are fine tuning themselves.
- Their skin is building fat. Get ready to pinch those chubby arms and cute cheeks!
- Their circulatory system is developed, but the digestive system won’t fully mature until after birth.
Pregnancy weeks 37- 40
- Your baby has reached a milestone: If they were born now, they would no longer be considered premature. Their organs are ready to function outside the womb.
- They’re gaining about half an ounce a day. Your little pumpkin will be about the size of a pumpkin when they make their world debut.
- Your baby’s lungs have matured—ready for their first breaths and laughter.
- Their reproductive system is fully formed.
- They’re curled up in the fetal position and primed to go!
- At 37 weeks, you’re considered full-term. Your new family member will be making their entrance any day now.
Third trimester body changes
- Moving around could be more challenging thanks to a bigger belly, backaches, and swelling feet.
- You may be peeing more and sleeping less.
- A dark line on your belly stretching from your belly button to your public area may start to make an appearance. It’s called the linea nigra, which means “black line” in Latin. It’s a normal part of pregnancy—blame it on those fluctuating hormones—and typically fades after the baby is born.1
- As your baby drops into the birth position, you may feel increased pressure in your pelvic area. This may also include “lightning crotch,” a sharp, shooting pain in the vagina, rectum, or pelvis.
- During your early third trimester, you may have Braxton Hicks contractions, also known as “false labor.” These contractions feel like your belly muscles are tightening. If your contractions don’t stop and become stronger and last longer, you could be going into labor.
- You may lose your mucus plug, which has been protecting your baby from outside germs. This often-unnoticed experience may look like a clear, yellowish discharge and is your cervix preparing for the big day.
- You may notice a blood-tinged discharge, known as the “bloody show,” which signifies labor could be very soon.
- Your water may break. It may trickle or gush. It means your amniotic sac has ruptured, and labor is just about ready to rock ‘n roll. If it doesn’t begin on its own, labor may be induced after your water breaks.
Third trimester checklist
This last leg of your pregnancy can bring a mix of excitement, nervousness, and exhaustion. Here are some things to check off your to-do list as your pregnancy journey winds down and the wondrous new one of parenthood begins.
Watch for labor indicators. It’s almost time to meet your little one. Keep an eye out for the following:
- Water breaking
- Loss of mucus plug
- The bloody show
- Regular contractions that become more uncomfortable, last 45 seconds, and come about 5-8 minutes apart.
Think you’re going into labor? Not quite sure? Call your doctor right away.
Try to de-stress. As your due date approaches, it’s natural to be a bit anxious. Meditating, deep breathing exercises, talking to family and friends, taking a walk, and other stress-reducing strategies can help promote calm.
Celebrate at your baby shower. It’s your day! Savor being the center of attention. Take plenty of pics and cherish all the joyful memories you’ll be able to share with your child someday. And since life is about to get pretty busy, try to send your thank you notes shortly after your celebration.
Find a pediatrician. Ask family and friends for recommendations, inquire about health insurance, verify credentials and experience, and meet with potential candidates to establish if they’ll be a good match for you and your newborn’s needs.
Increase doctor check-ins. Many women have biweekly checkups from weeks 28-36 and then weekly appointments until delivery.
Keep crushing that healthy eating. Your baby needs B vitamins, iron, calcium, omega-3 fatty acids, zinc, and other important nutrients for their healthy development. Proper hydration is also key for you and your baby’s health and can also help reduce constipation.
Start birthing classes. The third trimester is a great time to take a birthing class. A class can help you prepare for labor, delivery, and breastfeeding and ease some anxiety. It’s also an opportunity to meet other new expectant parents and share your concerns.
Gear up on baby gear. As any new parent will tell you, babies require a lot of stuff. Now is the time to shop for those newborn must-haves, from strollers, car seats, and baby monitors to adorable nursery decor. A tip: Shop after your shower since you may receive a lot of what’s on your registry.
Pack for the hospital. Plan for your hospital stay by packing a bag with comfy clothes, PJs, slippers, nursing items, toiletries, and personal care products that can help you feel like yourself.
Join Enfamil Family Beginnings
You got this, mama! The day you’ll be cuddling the baby you’ve carried for nine months is fast approaching and you’re as prepared as you’ll ever be. Enfamil Family Beginnings can help you get ready for the amazing changes parenthood will bring. It’s the perfect resource for new and expecting moms. Save on Enfamil products, track your bump and baby’s growth, and get helpful articles each week relevant to your journey. Join now.