Week 39 of Your Pregnancy

Pregnancy Week by Week: Week 39

Verywell / Bailey Mariner

At 39 weeks pregnant, you and your baby are considered full term. You may feel like “it’s time,” and it very well could be. Not all women stay pregnant long enough to deliver at the 40-week mark.

39 Weeks Pregnant Is How Many Months? 9 months and 3 weeks

Which Trimester? Third trimester

How Many Weeks to Go? 1 week

Your Baby's Development at 39 Weeks

At 39 weeks, a baby is almost 14 inches (35.4 centimeters) from the top of their head to the bottom of their buttocks (known as the crown-rump length), and baby's height is over 19 3/4 (50.5 centimeters) from the top of their head to their heel (crown-heel length). This week, baby weighs about 7 1/2 pounds (3,403 grams).

At 39 weeks pregnant, your baby is about the length of the zipper of a sleepsack
Verywell / Bailey Mariner 

Birth Weight and Length

It's important to know that the weight and length measurements provided above are approximate. Your baby may very well be larger or smaller than an average at birth, and that is still normal. The birth length (height) of a healthy newborn can range from 17 3/4 inches (45 centimeters) to nearly 22 inches (55 centimeters), and the birth weight of a healthy newborn can range from 5 1/2 pounds (2,500 grams) to 10 pounds (4,500 grams).

Organ Systems

By week 39, your baby’s organs are fully formed and capable of functioning normally outside the womb. But, that doesn’t make these final days of pregnancy any less important. During this time:

  • Baby's brain and lungs continue to grow and develop.
  • Baby is still gaining about 1/2 pound a week.
  • Baby is getting ready for labor and birth.

Immune System

Your baby's immune system is also getting stronger. During pregnancy, you pass antibodies to your baby to build their immune system and help them fight off illness and infection. While baby has been receiving your antibodies from the placenta since week 13, the majority of the antibodies you pass to them during pregnancy transfer during the last few weeks.

Full Term

At 39 weeks, your baby is "full term." A full-term baby is one that is born between 39 weeks and 40 weeks 6 days. Babies born during this time frame have the best health outcomes.

Explore a few of your baby's week 39 milestones in this interactive experience.

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Your Common Symptoms This Week

You're likely still experiencing most, if not all, of the third-trimester symptoms you've had up to this point, but on a more exciting note, your body is also likely making real strides in preparation for your baby's birth.

Effacement

At 39 weeks, your baby is more than likely head down and situated low in your pelvis. As baby's head gradually inches closer and closer to your cervix, the pressure should help prepare your cervix to begin softening, shortening, and thinning out. This process is called ripening or effacement.

Dilation

In order to birth your baby, your cervix has to efface (soften, shorten, and thin out) and open or dilate. For some women, effacement and dilation come on slowly and steadily over weeks. For others, it all happens rather quickly during labor.

Diarrhea

Changes in the cervix happen, in part, because you are experiencing an uptick of hormones called prostaglandins. Prostaglandins help get the cervix ready for labor and birth, but they can also bring about loose stools.

Self-Care Tips

Ready to birth that baby of yours? Once you're full term, it's usually safe to take steps to encourage labor.

Encouraging Labor

There are a few things you can do at home that may gently encourage baby’s exit. If your provider is not trying to keep you from going into labor for any reason, you can try:

  • Taking walks: Some believe that being upright and moving encourages baby to slide further down and put pressure on your cervix to get things moving along.
  • Stimulating your nipples: Nipple stimulation spurs the release of oxytocin, which can stimulate contractions. (You can massage your breasts, apply warm compresses, use a breast pump, or enlist your partner to help.)
  • Having sex: Some believe that the prostaglandins in semen can encourage labor. Others note that oxytocin released during orgasm is what can help coax baby out. Neither theory is scientifically proven. That said, if you’re up for it and it will help take your mind off of being 39 weeks pregnant, it is worth a try.
  • Take evening primrose oil: Evening primrose (Oenothera biennis) oil contains linolenic acid, which may stimulate the production of prostaglandins. While scientific evidence to support this is in short supply, it appears to be safe, but talk to your provider before starting this supplement.

Your Week 39 Checklist

  • Continue to take your prenatal vitamins and drink plenty of water.
  • Continue with your Kegel exercises and daily perineal massage.
  • Take a walk.
  • Try intercourse, orgasm, and/or nipple stimulation to help spur labor.
  • Take some time to relax before the big day.

Advice for Partners

Sexual intercourse, female orgasm, and nipple stimulation may help encourage labor. But all of the above likely won’t do a thing unless mom-to-be is relaxed and in the mood.

If she is medically cleared to go into labor (meaning her healthcare provider hasn’t explicitly said otherwise) and both of you are interested in trying to get things started in this manner, do what you can to make her feel at ease. But remember:

  • Intercourse is not allowed if your partner’s water has broken.
  • Intercourse is not advised if your partner is experiencing bleeding.
  • It’s her orgasm and pleasure that’ll spur the release of oxytocin.
  • Ejaculation needs to happen inside the vagina for semen’s prostaglandins to do their job.
  • Certain sex positions may be more comfortable for her than others.

At Your Doctor’s Office

You will have the usual measurements, checks, and discussions at this weekly visit, including:

  • Weight check
  • Blood pressure check
  • Urine test
  • Swelling check
  • Fundal height measurement
  • Listening to baby's heartbeat
  • Checking the position of the baby
  • Discussion of symptoms
  • Cervical examination
  • Answering your questions

Take this time with your provider to ask any lingering questions about labor and delivery. Of course, if you think of something later, you can always call the office.

Weight Gain

You are at the end of your pregnancy. If you were at a normal body mass index (BMI: 18.5–24.9) before getting pregnant, it is recommended that you gain approximately 25 to 35 pounds over the course of pregnancy. However, everyone is different. So, you may have gained more or less depending on your situation and your doctor's recommendation.

Stripping the Membranes

At 39 weeks, your physician or midwife may offer to strip or sweep your membranes. They can do this procedure during the internal exam if the cervix has begun to dilate.

To strip the membranes, your healthcare provider will use a gloved finger to gently separate the membranes that attach the amniotic sac to your uterine wall. This procedure can stimulate natural prostaglandins and get contractions started.

While not every doctor or midwife routinely offers the procedure, it may reduce the need for induction and lower your chance of being post-term (going past 40 weeks and your expected due date). Know, however, that the procedure may cause discomfort (akin to menstrual cramps) and you’ll likely experience some spotting up to three days afterward, but all of that is perfectly normal.

Upcoming Doctor’s Visits

The next time you see your doctor or midwife may very well be in the delivery room. But remember, a due date is a best-estimated guess.

If not, you'll be back in the office for another routine visit next week.

If you continue on past your due date, your provider may want to monitor you more closely and schedule you for some additional tests, such as:

Special Considerations

By 39 weeks, you're an old pro at being pregnant, but you still may have some questions or concerns about birth.

Chances of Childbirth This Week

You have an excellent chance of delivering this week or next week. A large study of over 34 million U.S. births between 2007 and 2015 showed that 54% to 60% of those expecting had their baby between 39 and 40 weeks.

Umbilical Cord Fears

Many mothers fear that the umbilical cord might wrap around baby’s neck, which is known as a nuchal cord. While it’s true that this is a common occurrence (present in 20% to 30% of births), a nuchal cord rarely impedes baby’s descent or delivery, according to research in the Journal of Midwifery and Reproductive Health.

What Experts Say

“The potential concern is not that baby can’t breathe, but that the blood flow through the cord would cease. But the two arteries and vein in the umbilical cord are protected by a thick substance called Wharton’s jelly, which cushions the vessels from serious damage.”

—Allison Hill, MD, OB/GYN

Most of the time, the umbilical cord is loosely wrapped, so your healthcare provider can easily slide it over baby’s head during delivery. If the umbilical cord is tightly wrapped, however, your physician or midwife may cut the cord before your baby is born.

A tightly wrapped cord is less common but more dangerous. It can cause complications in the baby such as low blood pressure, breathing difficulties, and, in some cases, death. Rest assured, however, that if the baby is in distress due to a nuchal cord, your doctor will deliver the baby right away and possibly through an emergency C-section.

A Word From Verywell

You've made it to full term, which means you can expect to meet your baby any day now. As most will tell you, however, it's still a bit of a waiting game. Some women find themselves feeling a little impatient and ready to go. If you're in that group, that's OK.

As long as your provider hasn't expressed any concerns, go ahead and try some of the safe methods to naturally kick start labor. Just do your best to enjoy yourself. Baby will still come on their own time, so even if you have to wait longer than you'd hoped, at least you had some fun in the meantime.

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Article Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
  • Allison Hill, MD. Email communication. October, November 2017.