What to Expect at 39 Weeks Pregnant: A Week-by-Week Guide

Quick take: At 39 weeks you’re almost at term, so your baby is fully formed and ready to be born. Expect a baby about the size of a small pumpkin, a few new aches, a possible “lightening” of the belly, and a handful of routine tests. Most signs of labor are clear – regular contractions, water breaking, or a bloody mucus plug – and it’s time to call your provider if any of these appear.

It’s 2 a.m., you’ve just felt a gentle tightening in your lower belly and wondered, “Is this the start of labor?” You’re not alone. The final week of pregnancy can feel like a roller‑coaster of excitement and anxiety, especially when you’re counting down the days to meet your baby.

In this guide we walk through everything you’ll see and feel at 39 weeks, from the baby’s size to the latest prenatal tests, the foods you should skip, and how to pack a hospital bag that makes you feel prepared. We’ll also answer the most common “what‑if” questions, so you can relax knowing exactly what to expect.

What are the signs of labor at 39 weeks, and how do I know if it’s preterm?

Labor at 39 weeks is considered full term, and the body usually gives clear cues. The three classic signs are:

• Regular contractions: Tightening that comes every 5 minutes or less, lasts 30–70 seconds, and gets stronger over time.
• Water breaking: A sudden gush or a slow leak of amniotic fluid, which can be clear, pink, or slightly blood‑tinged.
• Bloody mucus plug (show): A pink‑brown discharge as the cervix begins to open.

If you notice any of these, especially in combination, it’s time to call your provider. Preterm labor before 37 weeks is rare at this stage, but if you experience very frequent (every 2‑3 minutes) or painful contractions, or a sudden gush of fluid, contact your care team immediately.

Other subtle signs include:

• Lower‑back pressure or “nesting” urges.
• Increased pelvic pain that doesn’t ease with rest.
• Changes in the fetal heart rate pattern (see the next section).

Most women at 39 weeks notice a gradual increase in pressure rather than a sudden “onset.” Trust your instincts—if something feels different, give your provider a quick call.

Is it normal to have contractions at 39 weeks, and what does the fetal heart rate look like?

Y

The fetal heart rate (FHR) at 39 weeks typically ranges between 110‑160 beats per minute. A reassuring pattern shows a steady baseline with occasional accelerations when the baby moves. Decelerations—brief drops in rate—can happen during contractions but should return quickly to baseline.

Providers will monitor FHR during prenatal visits and at the hospital. If you notice a persistent slow heart rate (< 110 bpm) or prolonged decelerations, seek medical advice right away.

Remember, occasional “pings” are normal, especially after a meal or when you’re stressed. The key is consistency and the baby’s response to movement.

How much weight should I have gained by 39 weeks, and what are the nutrition guidelines?

Weight‑gain recommendations depend on your pre‑pregnancy body‑mass index (BMI). Below is a quick reference from the American College of Obstetricians and Gynecologists (ACOG):

By 39 weeks most women are within a few pounds of their target range. Sudden large gains after 36 weeks may signal excess fluid or gestational diabetes and should be discussed with your provider.

Nutrition wise, focus on:

• Protein: Lean meats, beans, tofu, and dairy (≈ 70 g daily).
• Complex carbs: Whole‑grain breads, oatmeal, quinoa—provide steady energy.
• Healthy fats: Avocado, nuts, olive oil for fetal brain development.
• Iron and calcium: Dark leafy greens, fortified cereals, low‑fat dairy.

Avoid:

• Unpasteurized cheeses, deli meats, and raw seafood (risk of listeria).
• High‑mercury fish such as shark, swordfish, king mackerel.
• Excess caffeine (> 200 mg/day) and sugary drinks.

Hydration is key—aim for at least 8‑10 cups of water a day. Small, frequent meals can ease nausea and heartburn, which often linger into the final weeks.

What tests are done during the 39th week of pregnancy?

Most providers schedule a final prenatal visit between weeks 38‑40. Typical assessments include:

• Blood pressure and weight check: Detect pre‑eclampsia or gestational hypertension.
• Fetal heart rate monitoring: Using a Doppler or electronic fetal monitor.
• Fundal height measurement: To confirm growth; at 39 weeks the uterus should measure about 38‑40 cm.
• Urine dipstick: Checks for protein, glucose, and infection.
• Group B Streptococcus (GBS) screening: If not done earlier, a swab is taken at 35‑37 weeks; the result guides intrapartum antibiotics.
• Blood work (if indicated): Hemoglobin, iron, and rubella immunity status.

Some clinicians also perform a non‑stress test (NST) or biophysical profile (BPP) if there are concerns about fetal growth or movement.

The goal of these tests is to ensure both you and the baby are healthy and to plan for a smooth delivery. If any results are abnormal, your provider will discuss next steps, which may include early induction or additional monitoring.

How to prepare a hospital bag at 39 weeks and what to expect when the baby drops?

Having a packed bag ready reduces stress when labor begins. Here’s a concise checklist:

• For you: Two comfortable maternity tops, a robe, slippers, nursing bra, and a few pairs of loose‑fit pants or a nightgown.
• Toiletries: Toothbrush, toothpaste, hairbrush, lip balm, moisturizer, and any skincare you love.
• Personal items: Phone charger, ID, insurance card, and a small amount of cash.
• For labor: Music playlist, headphones, a birth plan summary, and any comfort items (e.g., a birth ball, massage oil).
• For baby: Three newborn outfits, a going‑home outfit, a blanket, and a hat.
• Paperwork: Hospital registration forms, any consent forms, and a list of medications.

Pack the bag by week 37 so it’s ready to grab and go. Keep it by the front door or in the car.

“Lightening,” or the baby dropping into the pelvis, often occurs a few weeks before birth, but many women notice it at 39 weeks. You may feel:

• Reduced pressure on the diaphragm—easier breathing.
• Increased pelvic pressure or a “sinking” sensation.
• More frequent urination as the baby’s head eases against the bladder.

These changes are normal and usually mean the baby is getting into the best position for delivery. If you notice a sudden, dramatic drop accompanied by intense pain or a gush of fluid, call your provider right away.

What is the baby’s size at 39 weeks and how does the due date shift?

By 39 weeks the average fetus weighs about 7 lb (3.2 kg) and measures roughly 20 inches (51 cm) from crown to heel—about the size of a small pumpkin or a large mango. The head accounts for about one‑third of the total length, and the lungs are fully mature, which is why babies born at this stage have excellent respiratory outcomes.

Due‑date calculators can shift slightly as pregnancy progresses. While the original due date is based on a 28‑day menstrual cycle, most clinicians use the “first‑trimester ultrasound” date as the most accurate. At 39 weeks, the estimated due date may be adjusted by a few days if the ultrasound showed the baby’s growth deviating from the norm.

It’s common for the due date to be pushed back by up to a week if the baby’s size is smaller than expected, or moved forward if growth is ahead of schedule. Your provider will discuss any adjustments during the 39‑week visit.

Can I exercise at 39 weeks, and what are common symptoms and discomforts?

Gentle, low‑impact exercise remains safe for most women at 39 weeks, unless your provider has advised otherwise (e.g., placenta previa, pre‑eclampsia). Good options include:

• Short walks (10‑15 minutes) to keep circulation moving.
• Prenatal yoga or stretching—focus on breathing and hip‑opening poses.
• Swimming or water aerobics, which reduce joint stress.

Avoid high‑impact activities, contact sports, or deep squats that could strain the pelvic floor.

Typical discomforts in the final week include:

• Backache: The growing uterus shifts your center of gravity.
• Swelling (edema): Feet, ankles, and hands may puff up.
• Heartburn: Hormonal relaxation of the lower esophageal sphincter.
• Frequent urination: The baby’s head presses on the bladder.
• Braxton‑Hicks contractions: Irregular, painless tightening.

Simple remedies—warm compresses for back pain, elevating feet, and small, frequent meals—often bring relief. If swelling is sudden, severe, or accompanied by headaches, it could signal pre‑eclampsia and warrants immediate medical attention.

When can I expect labor after 39 weeks, and how many weeks until delivery?

Most pregnancies progress to labor between 39 weeks 0 days and 41 weeks 6 days. The average timing is around 40 weeks 3 days. If you haven’t gone into labor by 41 weeks, many providers discuss induction to reduce the risk of post‑term complications.

Statistically, about 60 % of women deliver within the first week after 39 weeks, and roughly 90 % do so by 41 weeks.

Factors that can influence timing include:

• Maternal age (younger mothers may go slightly earlier).
• First‑time (nulliparous) pregnancies often last a few days longer than subsequent pregnancies.
• Fetal position—breech presentations sometimes lead to earlier induction.

While you can’t predict the exact day, staying aware of the signs of labor and maintaining regular communication with your provider will keep you prepared for the inevitable arrival.

From our medical team: The last weeks of pregnancy are a time of rapid physical change, but the basics remain the same—stay hydrated, keep moving as feels comfortable, and trust your body’s signals. If any sign feels out of the ordinary—especially sudden, intense pain, a large gush of fluid, or a rapid increase in swelling—call your provider right away. Your health and your baby’s safety are the top priorities.

Myth vs. fact

Myth: “If my baby hasn’t arrived by 39 weeks, something is wrong.”

Fact: Full term is 39 weeks 0 days to 40 weeks 6 days. Most babies arrive within this window, and waiting a few more days is normal.

Myth: “I must stop all exercise at 39 weeks.”

Fact: Light, low‑impact activities like walking or prenatal yoga are safe for most pregnancies, unless your provider advises otherwise.

Myth: “All foods are safe in the final week.”

Fact: Unpasteurized cheeses, deli meats, and high‑mercury fish remain risky throughout pregnancy, even at 39 weeks.

Key takeaways

• At 39 weeks the baby is fully formed, averaging 7 lb and 20 inches long.
• Watch for regular contractions, water breaking, or a bloody mucus plug as signs of labor.
• Maintain a balanced diet, stay hydrated, and keep moving with gentle exercise.
• Pack your hospital bag by week 37 and keep it ready for a quick grab‑and‑go.
• Lightening may happen now—expect more pelvic pressure and easier breathing.
• Contact your provider if you notice sudden swelling, severe pain, or any fluid loss.

Frequently asked questions

Can you go into labor at 39 weeks?

Yes—full‑term labor often starts at 39 weeks 0 days, and many women deliver within the first week after this point.

What are the signs that labor is starting at 39 weeks?

Regular, increasingly strong contractions, a sudden gush of fluid, or a pink‑brown mucus plug are the most reliable indicators.

Is it safe to have sex at 39 weeks pregnant?

For most uncomplicated pregnancies, sex is safe up to the moment labor begins; however, avoid deep penetration if your provider has advised against it due to placenta previa or other concerns.

How much weight should I have gained by 39 weeks?

Weight gain depends on pre‑pregnancy BMI: roughly 34 lb for normal‑weight women, 23 lb for overweight, and 18 lb for obesity, with a few pounds left to go.

What tests are done in the 39th week of pregnancy?

Typical assessments include blood pressure, weight, fetal heart monitoring, urine dipstick, fundal height measurement, and a review of the Group B Streptococcus (GBS) screen.

When should I call my doctor at 39 weeks?

Call immediately for regular contractions (every 5 minutes or less), water breaking, sudden swelling, severe headache, or any rapid change in fetal movement.

When to call your doctor

If you experience any of the following, seek medical attention right away: regular contractions, sudden fluid loss, severe abdominal pain, a rapid increase in swelling, headache with visual changes, or a significant drop in fetal movement. This article provides general information and is not a substitute for personalized medical advice—always discuss your specific situation with your healthcare provider.

References

1. American College of Obstetricians and Gynecologists (ACOG). “Weight Gain During Pregnancy.” Practice Bulletin No. 229, 2020.
2. National Health Service (NHS). “What to expect in the last weeks of pregnancy.” Updated 2022.
3. Centers for Disease Control and Prevention (CDC). “Group B Streptococcus (GBS) Guidance for Pregnant Women.” 2021.
4. World Health Organization (WHO). “Recommendations on Antenatal Care for a Positive Pregnancy Experience.” 2016.
5. Royal College of Obstetricians and Gynaecologists (RCOG). “Management of labour at term.” Green-top Guideline No. 73, 2021.
6. Mayo Clinic. “Braxton‑Hicks contractions.” Accessed July 2023.
7. National Institute for Health and Care Excellence (NICE). “Antenatal care for uncomplicated pregnancies.” NG62, 2020.
8. American Academy of Pediatrics (AAP). “Safe caffeine consumption during pregnancy.” 2022.