39 Weeks Pregnant: Your Baby's Development

You've made it this far, and now that you're 39 weeks pregnant, your baby is considered full term. The end of the third trimester, and your pregnancy, is now in sight.

Your baby's lungs and brain are still developing and will continue to develop after she's born. In fact, her brain won't reach its full size for about another two years, and the lungs might not be mature until around the age of 3. Right now, the lungs are busy manufacturing surfactant to keep the air sacs from sticking together when she takes her first breath.

Your little one doesn't have much room to move around in your uterus now, so if you've noticed any changes in her movements, that's probably why. If you are feeling less movement than usual, you can always check with your healthcare provider for reassurance.

How Big Is Your Baby at 39 Weeks?

Your baby is about the size of a watermelon, but do remember that healthy, happy babies come in many different sizes.


Mom's Body at 39 Weeks Pregnant

At this point, you're probably feeling more than ready for your baby to be born! Some moms-to-be find walking, and moving in general, to be a struggle, thanks to all that baby weight and a belly that just won't quit. Try to move slowly and carefully, and get as much rest as you can. Sleep might not come easily, so try to save your energy by getting in some downtime or a short catnap during the day, if possible. If you're wondering how many months along you are at 39 weeks pregnant, you're either in your ninth month or tenth month, because the weeks of pregnancy don't fit evenly into full months.

Your uterus has expanded over the course of your pregnancy. It started out weighing about two ounces before you were pregnant, and it's now grown to weigh about two and a half pounds. After you give birth, it will shrink back to its pre-pregnancy size and settle back down below your pubic bone. After about six weeks, it should be back to its normal size.

39 Weeks Pregnant: Your Symptoms

  • Trouble sleeping. It may be more difficult to get a good night's sleep toward the end of your pregnancy. The size of your belly may make it hard to find a comfortable position, and nerves and anxiety can keep you up, too. Try to make your bed and bedroom as comfortable as possible, with plenty of extra pillows to prop you up and keep you comfortable.

  • Losing the mucus plug. At 39 weeks pregnant, losing the mucus plug can be one of the normal signs that labor is approaching, and it can happen anywhere from a few hours to a few weeks before labor actually starts. A clear, pinkish, or slightly bloody vaginal discharge might be the mucus plug, but not all moms-to-be will notice it. This plug seals the cervix during pregnancy and keeps bacteria out of the uterus. When it detaches, you might see it in one blob or in several parts on your panties or on the toilet paper after you wipe. If you notice anything more than this slightly bloody discharge, contact your healthcare provider right away.

  • Water breaking. We've all seen it in the movies — when the character's water breaks, you know the baby is coming soon! This discharge can feel like a trickle or gush of fluid, and it means that the amniotic sac around your baby has broken, the amniotic fluid is leaking, and your labor is starting. If your water breaks, it's time to call your healthcare provider, who will let you know what to do next. If the leaked amniotic fluid has a foul odor or if you're running a fever when your water breaks, be sure to let your healthcare provider know, because this could be an indication of an infection known as chorioamnionitis.

  • Preeclampsia Some moms-to-be are diagnosed with this blood pressure disorder in the last weeks of pregnancy. A few possible symptoms at 39 weeks pregnant include swelling of your face and hands, headaches, nausea and vomiting, sudden weight gain, shortness of breath, and vision changes. Your healthcare provider has likely been checking your blood pressure regularly, and may continue to do so as needed in these final few weeks, but if you notice any of the symptoms described above, contact your provider right away.

39 Weeks Pregnant: Things to Consider

  • When you think you might be in labor, you'll want to start timing your contractions to make sure you're not experiencing Braxton Hicks contractions. In the early stages of labor, your contractions might come in 5- to 15-minute intervals and each contraction might last between 60 and 90 seconds. When your contractions occur at regular intervals and don't stop when you change positions, it's probably time to give your provider a call. As labor progresses, you'll probably find your contractions occur more frequently, and they might become more intense, too. To help you keep track, download and print our contraction tracking chart.

  • Be aware that, in some cases, your healthcare provider may recommend inducing labor. This could be because you or your baby have certain medical conditions, your labor is not progressing as it should, or you've gone past your due date. Your provider will be able to talk you through the procedure, its risks, and its benefits for your specific situation if this is something that you may need, even if it's not exactly what you had planned.

  • Once you're in labor, you may find some positions more comfortable than others. For example, some moms-to-be give birth in a hospital bed while reclining with their feet in stirrups, and others may use a birthing chair or stool, depending on the policies and available facilities at the local hospital or birth center. If available, you may also be able to try using a birthing ball that lets you rock back and forth when contractions strike. You might also like to try squatting, standing, or kneeling during labor, if your hospital staff give you the OK to do so. You may have a birth plan that outlines how you want to go through labor and some possible comfort techniques, but keep in mind that your preferences may change when you are actually in labor, and that you'll need to be flexible when the time comes.

  • It's possible that well-meaning friends and family members may start offering suggestions on how to bring on labor at 39 weeks pregnant. Your best friend may insist she went into labor right after enjoying a spicy meal, or a relative may suggest having sex or taking a long walk. There's actually no medical evidence that eating spicy foods, taking long walks, or having sex will bring on labor. If you do have any questions or concerns about when labor will start, it's best to talk to your healthcare provider.

39 Weeks Pregnant: Ask Your Doctor

  • How much should my baby be moving in these last few weeks of my pregnancy?

  • If I give birth vaginally, will labor and childbirth be in different rooms?

  • If my baby is in a breech position, what do you recommend?

  • What is an operative vaginal delivery? Is this something you recommend?

  • Will my birth partner or older children be allowed in the delivery room when I give birth?

  • Is photography or videography allowed in the delivery room?

  • What should I expect to happen in the first few hours after I give birth?

  • Can I expect skin-to-skin contact with my baby immediately after she's born?

How we wrote this article The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.