Our Baby Journey39 weeks pregnant
39 weeks pregnant is about 9 months. It falls in the ninth month of pregnancy. You are in week 39 of 40, in the third trimester. Here is what is happening with your baby and your body this week.
Your baby is about the size of a watermelon.
Length: about 50.7 cm (20 in) from crown to heel · Weight: about 3.3 kg (7.3 lb)
Your baby at 39 weeks
The baby is full term. The brain and lungs are still maturing, even now.
Your baby is now full term, the stage linked with the best outcomes for most newborns. Even so, important growth continues. The brain is still developing fast, and the lungs keep producing surfactant to help with those first breaths. Fat stores built up in these final weeks also help your baby keep blood sugar steady after birth.
Your baby has a firm grip, coordinated sucking, and reflexes like startling at loud sounds. A healthy layer of fat helps keep the body warm, and the skin is losing much of its earlier redness, though skin tone can keep changing for a while after birth.
Late in pregnancy, hormones from your baby and the placenta are thought to play a role in signaling that labor is ready to start. Babies vary widely in size near term, and many healthy babies are born well above or below the average weight.
Your body at 39 weeks
Labor could start any day. Contractions may become stronger and more regular.
You may be feeling heavy, tired, and ready to meet your baby. Contractions may be getting stronger or more frequent, but true labor contractions come at regular intervals, get closer together, and do not ease with rest. Some people feel a sudden drop in energy while others feel restless. You may also have diarrhea or loose stools as hormones change before labor. Keep your phone charged and your bag by the door, and remember that an early stage of labor often lasts many hours, especially with a first baby, so you may spend much of it at home.
Your belly at week 39
In month 9 (weeks 36–40) your baby may drop lower into your pelvis, so your bump can look lower than before. This is more common in a first pregnancy. Breathing may get easier, but you will feel more pressure low in your belly and pelvis, and fundal height may stop increasing or dip slightly.
Belly size and shape vary a lot depending on your build, whether this is your first pregnancy, your baby's position and the amount of amniotic fluid. At checkups your doctor or midwife may measure your fundal height to track your baby's growth, and may arrange an ultrasound if the measurement is quite different from what they expect.
Symptoms at 39 weeks pregnant
- Contractions that may start to come more regularly
- Loose stools or an upset stomach
- A show of mucus, possibly blood-tinged
- Strong pelvic pressure
- Restlessness or very low energy
Checkups around week 39
Weekly visits continue, though schedules vary by country. Your provider may discuss a membrane sweep or the option of induction, and the evidence on timing, since some guidance supports offering induction from 39 weeks for low-risk pregnancies. They will also confirm when to call and where to go once labor begins.
Tips for week 39
- Time your contractions to know when to go in.
- Stay calm and keep your support person informed.
- Eat light meals and stay hydrated.
Common symptoms in the third trimester
The third trimester runs from week 28 until birth, usually around week 40. Your baby gains most of their weight, their lungs mature, and your body prepares for labor. Not everyone has every symptom, and it is normal for symptoms to come and go. Common ones include:
- Shortness of breath as your uterus presses up on your diaphragm
- Braxton Hicks (practice) contractions
- Swelling of the feet and ankles
- Trouble sleeping and getting comfortable
- Pelvic pressure and pain
- Needing to urinate more often again
- Heartburn and back ache
Read the full third trimester guide.
When to call your doctor or midwife
Contact your healthcare provider or maternity unit straight away, or get emergency care, if you have:
- Vaginal bleeding
- Severe or persistent abdominal pain or cramping
- A severe headache, blurred vision, or sudden swelling of your face, hands or feet
- A fever of 38°C (100.4°F) or higher
- Fluid leaking from your vagina
- Severe vomiting where you cannot keep fluids down
- Your baby moving less than usual or a change in their pattern of movements (later in pregnancy)
- Regular contractions before 37 weeks
- Pain or burning when you urinate
- Feeling very low, anxious, or having thoughts of harming yourself
Have a question about week 39?
Ask our AI pregnancy assistant about symptoms, nutrition, scans or anything else on your mind this week.
Frequently asked questions
How big is my baby at 39 weeks pregnant?
At 39 weeks pregnant, your baby is about the size of a watermelon. That is about 50.7 cm (20 in) from crown to heel, weighing about 3.3 kg (7.3 lb).
How big is my belly at week 39 of pregnancy?
In month 9 (weeks 36–40) your baby may drop lower into your pelvis, so your bump can look lower than before. This is more common in a first pregnancy. Breathing may get easier, but you will feel more pressure low in your belly and pelvis, and fundal height may stop increasing or dip slightly. Bump size, shape and when you start to show vary a lot from person to person.
What are the signs of labor at 39 weeks?
True labor usually brings contractions that are regular and get stronger, longer, and closer together, and do not stop when you rest or change position. Other signs include your waters breaking and a show of mucus. Your provider will tell you when to come in, often based on how close together your contractions are. Call right away if you have bleeding or reduced movements.
Should I be induced at 39 weeks?
For some people with a low-risk pregnancy, induction at 39 weeks is an option rather than waiting for labor to start on its own. It has possible benefits and drawbacks, and practices vary between hospitals and countries. Talk to your doctor or midwife about your health, your preferences, and what an induction would involve before deciding.
Is it normal for my baby to move less at 39 weeks?
No. It is a myth that babies move less before labor. Movements may feel different because there is less room, but your baby should keep moving as much as usual right up to and during labor. If you notice your baby moving less or the pattern changes, contact your maternity unit or provider straight away. Do not wait until the next day.
What trimester is 39 weeks pregnant?
Week 39 is in the third trimester, which covers weeks 28 to 40.
How many months is 39 weeks pregnant?
39 weeks pregnant is about 9 months. It falls in the ninth month of pregnancy. The ninth month covers weeks 36 to 40. Pregnancy is about 40 weeks, or roughly 9 months, counted from the first day of your last period.
This page is general educational information and is not a substitute for advice from your doctor or midwife. Every pregnancy is different, and baby sizes are approximate averages. Last updated 2026-11-07. See our medical disclaimer.