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Third trimester

39 weeks pregnant

At 39 weeks 0 days to 39 weeks 6 days, your pregnancy has reached full term, which ACOG defines as 39 weeks 0 days to 40 weeks 6 days. Labor could begin at any time, though many people go on to 40 weeks or beyond. Early signs such as a show or more discharge don't always mean labor is close.

This page covers 39 weeks 0 days to 39 weeks 6 days (39+0 to 39+6), counted from the first day of the last period. Check how far along you are

Enter it to see the calendar dates of your week 39.

Botanical illustration of a winter melon

About the size of a winter melon

Typical estimated weight 3.43 kg (7 lb 9 oz) at 39+0, about 3.59 kg (7 lb 15 oz) by 39+6. This is the 50th centile; healthy babies commonly vary by about 12.7% either way.1

A reference value, not a measurement of your baby.

How your baby is developing

  • Your baby's skin, which was almost see-through a few weeks ago, now has a tougher, more solid outer layer. This helps protect the internal organs and control temperature.2
  • A white, waxy coating called vernix protects the skin and helps your baby move through the birth canal. Some babies are born covered in it, while for others it is mostly gone.2
  • Head hair may be getting coarser and thicker, and fingernails may now reach past the fingertips.3
  • Small breast buds are present in babies of both sexes around this time. This is expected.3

Changes you may notice

Everyone’s experience is different. You may notice some of these, or none.

  • You may notice more vaginal discharge. It should be thin, white and not smell much.2
  • A show is a sticky blob of mucus, often pink or slightly bloody, that used to plug your cervix. It can be an early sign that labor is on its way, but labor may follow quickly or take a few days, and some people never notice one.2,4
  • Back pain and more pressure low in your bump are common as your baby moves down into your pelvis. Some people also get sudden bursts of energy and a strong urge to get things ready.2
  • Your baby should keep moving right up to and during labor. Call your midwife or maternity unit straight away if movements slow down, stop or change, even in the middle of the night.5

Care around this week

  • UK: after 39 weeks, your midwife or doctor may offer a membrane sweep. During an internal exam, they sweep a finger around your cervix to separate the membranes, which releases hormones that may start labor. It can be uncomfortable, and some cramping or light bleeding afterward is possible.6,7
  • US: induction at 39 weeks has been studied in low-risk pregnancies. In a large US trial of first-time parents with low-risk pregnancies, induction at 39 weeks did not significantly reduce a combined measure of serious problems for the baby, but fewer people in the induction group had a cesarean birth. Whether this suits you is a decision to make with your care team.8
  • Treat these as an emergency and call your midwife or doctor: vaginal bleeding, a severe headache that won't go away, vision problems, pain just below the ribs, extreme swelling, severe itching, persistent stomach pain, or a temperature above 37.5°C (99.5°F) without cold or flu symptoms.2

Questions to ask your provider

  • Would a membrane sweep be offered to me, and when?
  • What are the pros and cons of induction at 39 weeks in my situation?
  • When do you want me to call once contractions start?
  • What happens at the birth if my baby needs extra checks?
When to contact your provider straight away

Call 911 (US) or 999 (UK) in an emergency, such as heavy bleeding or bleeding with severe pain, a seizure, chest pain, or severe trouble breathing.10,11,12,13

These symptoms are not always serious, but each one needs prompt advice from your provider, midwife or maternity unit (or NHS 111 in the UK if you cannot reach them) rather than waiting for your next appointment, and it helps to tell them you are pregnant.

  • Vaginal bleeding or spotting at any stage of pregnancy. Call 911 or 999 if the bleeding is heavy or comes with severe belly pain, shoulder pain, or feeling faint or dizzy.12,14
  • Fluid leaking or gushing from your vagina, or discharge that is unusual for you. Get checked straight away if the fluid is greenish, colored or smells bad.4,12,13,15
  • Your baby moving less than usual, not moving, or a change in their usual pattern of movements. Call immediately, even in the middle of the night, and do not use a home Doppler to check yourself.5,12
  • A severe headache that does not go away with simple painkillers or gets worse, or sudden changes in your vision such as blurring or seeing flashing lights.10,12,13
  • Sudden swelling of your face, hands or feet, or swelling, redness or pain in a leg.10,12,13
  • Belly pain that is severe or does not go away after resting, or pain just below the ribs.10,12,16
  • Regular tightenings or contractions, period-type pains, or backache that is unusual for you before 37 weeks, which can be signs of preterm labor.15,16
  • A fever of 100.4°F (38°C) or higher, or feeling hot, cold or shivery.12,13,15
  • Shortness of breath that comes on suddenly or happens when you lie flat, chest pain, a racing or pounding heart, or dizziness or fainting.12,13
  • Very itchy skin, especially on the palms of your hands or soles of your feet, or itching that is worse at night.17
  • Being sick so often that you cannot keep food or drink down, or signs of dehydration such as dark urine, peeing very little, or feeling dizzy.12,18
  • Thoughts of harming yourself or your baby. Get help right away, and call 911 or 999 if you think you might act on them.12,19

Questions about 39 weeks

Is 39 weeks full term?

Yes. ACOG defines full term as 39 weeks 0 days to 40 weeks 6 days. Weeks 37 and 38 are early term.9

What is a membrane sweep?

It's an internal exam where a midwife or doctor sweeps a finger around your cervix to separate the membranes from it. This releases hormones that may start labor. In the UK it's usually offered after 39 weeks, and it can be uncomfortable.6,7

Should I be induced at 39 weeks?

There's no single answer. A large US trial found that inducing low-risk first-time parents at 39 weeks led to fewer cesarean births without significantly changing serious outcomes for babies. Your care team can talk through what it would mean for you.8

Sources

  1. In utero analysis of fetal growth: a sonographic weight standardRadiology 181(1):129–133, 1991
  2. Week 39NHS Best Start in Life
  3. Fetal developmentUS National Library of Medicine
  4. Signs of going into labourNHS Best Start in Life
  5. Your baby's movementsNHS (England)
  6. Inducing labourNHS (England)
  7. Inducing labour (NG207), table 1National Institute for Health and Care Excellence, 2021
  8. Labor induction versus expectant management in low-risk nulliparous women (ARRIVE trial)New England Journal of Medicine 379(6):513–523, 2018
  9. Committee Opinion No. 579: Definition of Term PregnancyAmerican College of Obstetricians and Gynecologists, 2013
  10. Pre-eclampsiaNHS (England)
  11. Epilepsy and pregnancyNHS (England)
  12. Urgent Maternal Warning Signs and Symptoms (Hear Her campaign)US Centers for Disease Control and Prevention
  13. Pregnancy symptoms you need to get help forNHS (England)
  14. Vaginal bleeding in pregnancyNHS (England)
  15. Premature labour and birthNHS (England)
  16. Stomach pain in pregnancyNHS (England)
  17. Itching in pregnancyNHS (England)
  18. Severe vomiting in pregnancyNHS (England)
  19. Depression in pregnancyNHS (England)

Links checked November 12, 2026. Citing a source does not mean it endorses this site.

Written from the sources above and checked against them on 2026-11-12. Not reviewed by a clinician. Our editorial policy