Third Trimester of Pregnancy

As your belly continues to grow, so does your excitement! Curious what happens during the third trimester of your pregnancy? Turn to our guides for information and expert advice on how to prepare for childbirth and care for a newborn.
ByThe Bump Editors|Updated November 10, 2023
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Image: Léa Jones

Key Highlights for the Third Trimester

The third trimester is exciting and beautiful and weird and scary; you’ll feel all the emotions as you approach the day you get to meet baby. In the meantime, expect to be uncomfortable. Your bump will continue to expand, you’ll have aches and pains and you’ll experience all sorts of new or returning symptoms (hello again heartburn, spider veins and frequent urination). Meanwhile, baby’s organs and systems will continue to mature and develop as the weeks go by. Prenatal visits will become more frequent, and you’ll want to be diligent about attending all appointments. Your doctor or midwife will continue to monitor your health and baby’s well-being, and you’ll get some important tests and revealing updates. Time is simultaneously flying and crawling—hang in there, you’re at the home stretch!

When Does the Third Trimester Start and End?

The third trimester begins on day one of week 28. While pregnancy is generally considered a 40-week journey, lots of babies arrive earlier, and some stay put past their due date. Of course, it’s also important to remember that due dates are estimates, so it’s totally normal if baby doesn’t arrive on the day you’ve had circled on your calendar for months. That said, most doctors won’t let you go beyond 42 weeks, and may suggest medically inducing labor before that point.


Third Trimester Symptoms

The finish line is nearing—baby will be in your arms before you know it! But first: a few fun surprises. Yes, the third trimester is chock full of unexpected new symptoms (oh joy!). Rest assured, though, that these slightly unpleasant developments are getting you closer to delivery day.

Braxton Hicks contractions

Before you experience real labor contractions, you may get some practice in the form of Braxton Hicks. These irregular contractions can start some time in the second or third trimester, and help to tone the muscles of your uterus and prepare your cervix for birth.


If a friend comments that you’re suddenly carrying lower, you may have experienced lightening or “dropping” in late pregnancy. This is when baby drops into the lower pelvis in preparation for delivery. Not only will your bump look lower, you may feel lighter too. You might even find it easier to breathe and eat now that baby isn’t all up in your ribs! That said, you’ll probably have to pee more often, as baby presses down on your bladder.

Lightning crotch

Toward the end of pregnancy, you might experience random jolts or zaps of pain in your crotch region. Lightning crotch is normal, common and completely harmless, but it may catch you off guard. The good news: It doesn’t last long. It’s a momentary discomfort, and changing positions should help.


Baby Development in the Third Trimester

Baby is getting bigger and their body begins to fill out a bit with a layer of brown fat. Meanwhile, their organs continue to mature, especially the lungs which helps them with their practice breathing. Baby’s reflexes are developing, and their five senses become largely functional (they love the sound of your voice!). Their bones continue to harden and their cartilage gets firmer. Around 37 weeks, meconium (aka baby’s first poop) begins to form. Suffice it to say, a lot is happening behind the scenes to get baby ready for their big debut.

What to Avoid During the Third Trimester

Generally speaking, you’ll want to avoid the same things in the third trimester that you’ve been steering clear of all along. That means no alcohol, smoking or illicit drug use. You’ll want to continue staying away from unpasteurized cheeses and juices, deli meats, raw fish and a few other risky foods. Avoid overly strenuous physical work and exercise, and any activity that raises your core body temperature (no dips in the hot tub). You also continue to get a free pass from changing the cat litter for a while. Finally, talk to your doctor or midwife before traveling in the third trimester. If things are progressing as expected, your provider may give you the green light to hop on a flight up until 34 to 36 weeks; just keep in mind that some airlines have their own policy regarding third-trimester air travel.

Frequently Asked Questions

Third Trimester
You’ve been doing this whole pregnancy thing for many months now. But the more time that goes by, and the closer you get to the finish line, the more questions you have. Here are some common things you might be wondering about now:

Are there ways to naturally induce labor?


It’s the end of the line, your due date has arrived (or potentially past) and you’ve got that stick-a-fork-in-me feeling. Are there ways to naturally induce labor? While nothing is guaranteed, there are some safe ways to try to encourage the process along. Walking and other moderate exercise can help. Sex may also encourage progress: Orgasms release oxytocin, which could jumpstart contractions. Moreover, prostaglandin in semen may ripen the cervix. Whatever you try, make sure to get signoff from your doctor or midwife first—some commonly shared options aren’t recommended, including taking certain herbs.


What should I pack in my hospital bag?


What should I do if I think I’m in labor?

When to Reach Out to Your Doctor in the Third Trimester

Undoubtedly, the third trimester will be uncomfortable. Aches and pains are par for the course, but there are a few red flags to watch for. If abdominal pain is severe and unrelenting, if you have regular contractions before 37 weeks or experience significant vaginal bleeding or leaking of fluid, contact your doctor right away; these may indicate preterm labor. Also reach out if you are experiencing blurred vision, headaches and swelling, as these symptoms could indicate preeclampsia, a complication typically marked by high blood pressure. Finally, seek medical attention if you notice a major reduction in baby’s movement (less than 10 kicks in two hours) when doing kick counts.

Third Trimester Checklist

Keep up with all regular prenatal visits and appointments, and get the group B strep test

Start doing fetal kick counts

Begin practicing Kegels, if you haven’t yet

Draft a birth plan if you haven’t yet

Send baby shower thank-you notes

Take a childbirth class, and consider signing up for infant CPR and breastfeeding classes

If you want to bank baby’s cord blood, order your kit

Interview pediatricians and choose one for baby

Hire a doula if you’d like to have one in the delivery room

Purchase any items from your registry that you’ll need

Wash baby’s newborn clothes with baby-safe detergent

Assemble important baby gear, like the crib

Pack your hospital bag

Stock up on supplies you’ll need for your postpartum recovery

Learn the signs of labor


Mayo Clinic, 3rd Trimester Pregnancy: What to Expect, March 2022

Northwestern Medicine, Staying Comfortable in the Third Trimester

Johns Hopkins Medicine, The Third Trimester

Mayo Clinic, Fetal Development: The 3rd Trimester, June 2022

Mayo Clinic, Overdue Pregnancy: What to Do When Baby’s Overdue, July 2022

StatPearls, Braxton Hicks Contractions, August 2022

Alberta Health Services, Pregnancy: Dropping (Lightening), February 2022

American Pregnancy Association, Lighting Crotch Pain During Pregnancy

Handbook of Experimental Pharmacology, Brown Adipose Tissue, April 2018

Cleveland Clinic, Newborn Reflexes, June 2022

The University of Texas Southwestern Medical Center, Womb with a View: Sensory Development in Utero, August 2017

Cleveland Clinic, Meconium, September 2022

Centers for Disease Control and Prevention, Substance Use During Pregnancy, May 2022

National Institutes of Health, Substance Use While Pregnant and Breastfeeding, April 2020

American Pregnancy Association, Foods to Avoid When Pregnant

The American College of Obstetricians and Gynecologists, Exercise During Pregnancy, March 2022

American Pregnancy Association, Hot Tubs During Pregnancy

Centers for Disease Control and Prevention, Toxoplasmosis: Pregnancy FAQs, December 2022

Johns Hopkins Medicine, Traveling While Pregnant or Breastfeeding

The American College of Obstetricians and Gynecologists, Air Travel During Pregnancy, August 2018

Journal of Education and Health Promotion, The Effect of Walking During Late Pregnancy on the Outcomes of Labor and Delivery: A Randomized Clinical Trial, 2021

Cleveland Clinic, Oxytocin, March 2022

Mayo Clinic, Labor Induction, May 2022

The University of Texas Southwestern Medical Center, The Truth About “Natural” Ways to Induce Labor, April 2017

American Pregnancy Association, False Labor

March of Dimes, Stages of Labor, March 2019

Alberta Health Services, Belly Pain in Pregnancy: Care Instructions, February 2022

Mayo Clinic, Preterm Labor, February 2022

Cleveland Clinic, Preeclampsia, October 2021

American Pregnancy Association, Counting Baby Kicks

U.S. Department of Health and Human Services, Prenatal Care, February 2021

The American College of Obstetricians and Gynecologists, Group B Strep and Pregnancy, July 2019

American Pregnancy Association, Kegel Exercises

Mayo Clinic Health System, The Importance of A Birth Plan, February 2022

Family Doctor (American Academy of Family Physicians), Birthing Classes, February 2021

Cleveland Clinic, Cord Blood Banking, August 2022

Nemours KidsHealth, Choosing A Pediatrician for Your New Baby, September 2019

The American College of Obstetricians and Gynecologists, Approaches to Limit Intervention During Labor and Birth, February 2019

Healthy Children (American Academy of Pediatrics), Car Seats: Information for Families, May 2023

American Pregnancy Association, Signs of Labor


More About the Third Trimester

Baby will be here before you know it, so it’s important to finalize your plans during the third trimester. Explore our articles below to make sure you have all your bases covered before baby arrives.


When it comes to labor and delivery, you likely have a lot of questions. Read our articles below to help you know what to expect when the big day comes.


There’s more to delivering a baby than just showing up at the hospital. How do you feel about pain medication? Who do you want in the delivery room? Our articles take you through your birth plan options to inform and empower you and help make your childbirth experience a beautiful one.


Labor and delivery are top of mind for mamas in their third trimester, and it can help to hear from others who’ve been through it before. We feature birth stories from real parents like you, so you can ready yourself and take heart knowing you’re about to join a community of amazing mamas.


Birth announcements can be just as exciting and creative as pregnancy announcements, with some parents choosing to keep it hush-hush for a few extra days or weeks.


When it comes to pregnancy, it's natural to feel nervous. If you're worried about pregnancy complications, the first thing you need to remember is this: you're not alone.


Third Trimester Videos

Whether you’re wondering what happens during your third trimester or looking for advice on preparing for labor, we’re here to help. Click play on the videos below to find out more.

Third Trimester Tools

Starting to feel contractions? Exciting! But it doesn’t necessarily mean it’s time to head to the hospital just yet. To help you gauge how far apart your contractions are, use our handy Contraction Counter tool below. Still searching for the perfect baby name? Try our baby name finder.


Community Forums

Feeling nervous? Excited? A little bit of both? Join our discussion forums, like our third trimester forums and birth month clubs, to chat with real-life parents like you. Ask questions, offer advice and create lifelong connections.

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