40 Weeks Pregnant

At a Glance: Week 40

Trimester: Third (full term). Baby's size: About the size of a small pumpkin — approximately 50–51 cm (19.7–20.1 inches) head-to-heel and weighing around 3,400–3,600 grams (7.5–7.9 pounds), though full-term babies vary widely.

You have officially reached your estimated due date. Your baby is fully developed and ready for life outside the womb. Their organs are mature, fat stores are built up for temperature regulation, and the reflexes needed for breathing, sucking, and swallowing are in place. While only about 4% of babies arrive exactly on their due date, you can expect to meet your baby within days to about two weeks from now.

Your Baby's Development This Week

At 40 weeks, your baby is considered full term and fully prepared for birth. Most major development is complete; the focus now is on final maturation and weight gain — your baby may add 14–28 grams (0.5–1 ounce) per day in this final stretch.

• Brain: Continues to develop rapidly. The brain at birth is only about 25% of its adult size and will grow significantly in the first year. Neural connections are forming at a remarkable pace, preparing for the sensory flood of life outside the womb.
• Lungs: Fully mature, producing surfactant that allows the air sacs to inflate and stay open for the first breath.
• Skin: Most of the vernix caseosa (waxy protective coating) has been shed, though some may still be present in skin folds. The skin is pink and smoother than weeks earlier.
• Eyes: Can focus on objects 20–30 cm away — roughly the distance to your face during feeding. Color vision is limited at first; high-contrast patterns are easiest to see.
• Bones: All bones are formed but skull plates remain flexible and overlap slightly to fit through the birth canal. This is why newborns often have cone-shaped heads, which round out over the first weeks.
• Reflexes: Rooting, sucking, grasping, and the startle (Moro) reflex are present and will be tested at the first newborn exam.

Your Body and Symptoms This Week

Week 40 brings a combination of late-pregnancy discomforts and pre-labor signs. Common symptoms include:

• Braxton Hicks contractions: Often more frequent and intense as your uterus prepares for labor. Unlike true labor, they are irregular and ease when you change position.
• Pelvic pressure and "lightning crotch": Sharp, sudden pelvic pain from the baby pressing on nerves as their head engages deeper.
• Loss of the mucus plug: A thick, sometimes blood-tinged discharge. This can happen days or hours before labor — or sometimes weeks before.
• Bloody show: A small amount of pink or brown-tinged mucus, often a sign that the cervix is starting to dilate.
• Backache: Lower back pain that comes and goes, sometimes radiating to the front, can be an early sign of labor.
• Diarrhea or nausea: Your body may "clear out" in the day or two before labor begins, possibly due to hormonal shifts (prostaglandins).
• Difficulty sleeping: Discomfort, frequent urination, and pre-labor anxiety can disrupt sleep. Rest when you can during the day.
• Swelling: Some swelling in feet and hands is normal. Sudden, severe swelling — especially in the face — warrants immediate medical attention.

Nutrition: What to Eat and Avoid This Week

In the final week, continue prioritizing a nutrient-dense diet to support late-stage fetal growth and prepare your body for labor and recovery.

• Iron-rich foods: Lean red meat, lentils, spinach, and fortified cereals help build iron stores for potential blood loss during birth.
• Calcium: Dairy, leafy greens, almonds, and fortified plant milks support both baby's bone development and your own.
• Healthy fats: Avocado, olive oil, nuts, and fatty fish (salmon, sardines) support brain development and provide sustained energy.
• Complex carbohydrates: Oats, whole grains, and sweet potatoes provide steady energy — important if labor begins and you cannot eat much.
• Dates: Some research suggests eating 6 dates per day in the final 4 weeks may help cervical ripening and shorten labor.
• Hydration: Aim for 2–3 liters of water daily. Dehydration can trigger Braxton Hicks contractions and worsen swelling.

Continue to avoid: Raw or undercooked meats and fish, unpasteurized dairy, high-mercury fish (king mackerel, swordfish, shark), deli meats unless heated, raw eggs, alcohol, and excessive caffeine (limit to 200 mg/day per ACOG).

Movement and Exercise

Gentle movement at 40 weeks can help with comfort and may encourage labor to begin. ACOG recommends 150 minutes of moderate-intensity exercise weekly during uncomplicated pregnancies, scaled to your comfort level.

• Walking: Gentle walks help baby descend deeper into the pelvis and may encourage cervical change.
• Prenatal yoga: Gentle stretches, cat-cow, and supported child's pose ease back pain and open the hips.
• Birth ball exercises: Sitting and gently bouncing or hip circles on a birth ball can help baby into an optimal position.
• Pelvic tilts: Help relieve back pain and encourage baby's positioning.
• Swimming: Excellent low-impact full-body movement that relieves the weight of late pregnancy.

Avoid: High-impact activities, anything with fall risk, lying flat on your back for extended periods, and pushing through pain. Stop and call your provider if you experience contractions during exercise that do not ease, bleeding, fluid leakage, dizziness, or chest pain.

Mental and Emotional Wellbeing

The end of pregnancy is emotionally complex. You may feel impatient, excited, anxious, exhausted, or some swirling combination of all four. Hormonal shifts in preparation for labor can intensify emotions. This is a normal part of the transition.

Common emotional themes at 40 weeks include: anxiety about labor and birth, fear of going overdue or being induced, impatience with well-meaning "any baby yet?" messages, body image distress, and ambivalence about pregnancy ending. Some parents also feel sadness about leaving the pregnancy chapter behind.

Strategies that help: prioritize sleep where possible, limit social media and check-in messages if they feel pressuring, lean on your partner and support network, practice gentle breathing or meditation, and remember that this final phase is temporary. If you experience persistent low mood, panic, intrusive thoughts, or thoughts of harm, contact your provider immediately — perinatal mental health support is available.

Common Concerns and When to Call Your Doctor

Call your provider or go to the hospital immediately if you experience any of the following at 40 weeks:

• Decreased fetal movement: Fewer than 10 movements in 2 hours after eating or drinking and lying on your left side.
• Water breaking: Especially if fluid is green, brown, or has a strong odor (may indicate meconium or infection).
• Heavy bleeding: More than a small amount of pink or brown spotting.
• Severe headache, vision changes, or upper abdominal pain: Possible signs of preeclampsia.
• Regular contractions: Following the 5-1-1 rule (every 5 minutes, lasting 1 minute, for 1 hour) — or sooner if your provider has advised.
• Sudden severe swelling: Especially in the face or hands, with or without headache.
• Fever above 38°C (100.4°F): Could indicate infection.
• Persistent severe pain: Especially in the upper right abdomen.

Tests and Appointments This Week

At 40 weeks, you'll likely have a weekly prenatal visit. Typical components include:

• Blood pressure check and urine test for protein and glucose
• Fundal height measurement and baby's heart rate via Doppler
• Discussion of fetal movement patterns
• Optional cervical check for dilation, effacement, and baby's position
• Discussion of membrane sweeping (a procedure that may help start labor naturally)
• Planning for what happens if you go past your due date — typically a non-stress test (NST) and biophysical profile (BPP) to monitor baby's wellbeing
• Conversation about induction timing if labor does not begin spontaneously by 41 weeks

Tips for Week 40

• Pack and double-check your hospital bag. Include ID, insurance cards, phone charger, comfortable clothes for going home, toiletries, snacks for partner, and a coming-home outfit for baby.
• Install the car seat. Many hospitals will not discharge you without proof of a properly installed seat — local fire or police stations often offer free installation checks.
• Prep easy meals. Stock the freezer with simple meals or arrange a meal train for the first weeks postpartum.
• Track movements daily. Set aside time once or twice a day to count baby's movements in a calm position.
• Rest, rest, rest. Labor is physically demanding. Sleep and conserve energy as much as you can.

Preparing for What's Next

As you wait for labor to begin, focus on the immediate postpartum period. Make sure you have: postpartum supplies (heavy pads, peri bottle, comfortable underwear), nursing supplies if breastfeeding (nipple cream, nursing bras, breast pads), newborn essentials (diapers in newborn and size 1, wipes, swaddles, a few onesies), and a pediatrician selected for baby's first visit (usually within 3–5 days of birth).

Discuss postpartum support with your partner and family: who will help in the first 2 weeks, who will handle visitors, how meals will be managed, and what your boundaries are around hospital and home visits. Plan for the "fourth trimester" — the first 12 weeks of recovery and bonding with your newborn.

Frequently Asked Questions About Week 40