Pregnancy
37 Weeks Pregnant
At 37 weeks, your baby is the size of a Swiss chard. Learn about early-term development, lightening, Braxton Hicks, and how to recognize true labor.
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This article is for general information and is not a substitute for professional medical advice. Always consult your pediatrician or doctor about your child.
Sources: WHO, CDC, AAP and NHS guidance. Recommendations differ between countries — for local advice see the NHS or ACOG.
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At a Glance: Week 37
- Trimester: Third trimester (early term)
- Baby's size: About the size of a Swiss chard or a head of romaine lettuce
- Length: Approximately 48–49 cm (about 19 inches), crown to heel
- Weight: Around 2,800–2,900 grams (about 6.2–6.4 pounds)
Week 37 is a major milestone: your baby has reached the "early term" classification. While not technically full term (which begins at 39 weeks), babies born this week are generally well-developed and most can transition to life outside the womb with little or no intervention. The final weeks are about putting on weight, refining the lungs, and getting into birthing position.
Your Baby's Development This Week
At 37 weeks, almost every system is functionally mature, but some are still putting on the finishing touches. Here's what's happening inside:
- Lungs: The lungs are producing surfactant, the substance that keeps the air sacs from collapsing after birth. Most babies born at 37 weeks can breathe on their own, but a small percentage may need brief respiratory support.
- Brain: Brain development continues at a rapid pace. Between 35 and 40 weeks, brain weight increases by about a third. The cortex is folding and forming the grooves that support higher cognition.
- Digestive system: The intestines now contain meconium — the dark, tarry substance that will become your baby's first bowel movement. The digestive tract is ready to handle breast milk or formula.
- Skin: Most of the lanugo (the fine downy hair) has been shed and swallowed. Vernix caseosa (the white waxy coating) is thinning. Skin is becoming pinker and less wrinkled as fat continues to be deposited.
- Eyes and ears: Hearing is well-developed. Your baby recognizes your voice and may turn toward familiar sounds. The eyes can detect light and dark and will respond to bright light shone on your belly.
- Position: Most babies are now head-down (cephalic). If your baby is still breech at 37 weeks, your provider may discuss an External Cephalic Version (ECV) or planning for a cesarean delivery.
Your Body and Symptoms This Week
Your body is in active preparation for labor. You may notice several new sensations:
- Lightening: The baby drops into the pelvis, easing pressure on your lungs but increasing pressure on your bladder. For first-time pregnancies, this often happens 2–4 weeks before labor; for subsequent pregnancies, it may not happen until labor begins.
- Braxton Hicks contractions: These "practice" contractions become more frequent and noticeable. They're irregular and typically painless, though they can be uncomfortable.
- Pelvic pressure and "lightning crotch": Sharp, shooting pain in the pelvis caused by the baby pressing on nerves. Brief but uncomfortable.
- Swelling (edema): Hands, feet, and ankles may swell more, especially at the end of the day. Sudden severe swelling, particularly in the face, can be a sign of preeclampsia — call your provider.
- Frequent urination and constipation: Pressure on the bladder and slowed digestion are at their peak.
- Loose stools or nausea: Some people experience GI changes in the days before labor as the body prepares.
- Insomnia and vivid dreams: Hormonal shifts, discomfort, and anticipation make sleep difficult.
- Nesting instinct: A sudden burst of energy and urge to organize, clean, or prepare the home is very common in late pregnancy.
Nutrition: What to Eat & Avoid This Week
Your nutritional needs in week 37 focus on supporting your baby's final growth spurt and preparing your body for labor and recovery.
Key nutrients to prioritize:
- Iron: Continue iron-rich foods (lean red meat, lentils, spinach, fortified cereals). Iron stores will help you recover from blood loss during delivery.
- Calcium and vitamin D: Dairy, fortified plant milks, leafy greens. Your baby is finishing skeletal mineralization.
- Protein: Aim for 75–100 g per day to support tissue growth and recovery.
- Omega-3 (DHA): Low-mercury fish like salmon, sardines, or supplements — critical for brain development happening right now.
- Hydration: 2.5–3 liters of fluids daily. Dehydration can trigger Braxton Hicks and worsen swelling.
- Fiber: Whole grains, fruits, vegetables to combat constipation.
Foods to continue avoiding: raw or undercooked meat, fish, and eggs; unpasteurized dairy; high-mercury fish (shark, swordfish, king mackerel); deli meats unless heated; alcohol; excess caffeine (limit to 200 mg per day per ACOG).
Movement & Exercise
Gentle movement at 37 weeks supports circulation, reduces swelling, and may help the baby get into an optimal birthing position. Safe activities include:
- Walking: Short, regular walks help open the pelvis and may encourage labor when your body is ready.
- Prenatal yoga: Hip-opening poses (deep squats with support, cat-cow, butterfly) can help with labor preparation.
- Pelvic floor exercises (Kegels): Continue these to support postpartum recovery.
- Birthing ball: Sitting and gently bouncing on an exercise ball can be more comfortable than a chair and may help baby's positioning.
- Swimming: Excellent for relieving joint pressure and swelling.
Avoid: high-impact exercise, lying flat on your back for extended periods, anything with a fall risk (skiing, horseback riding, contact sports), and overheating. Listen to your body — if something hurts or causes shortness of breath, stop.
Mental & Emotional Wellbeing
It is completely normal to feel a mix of excitement, anxiety, impatience, and even fear at 37 weeks. The reality of labor and parenthood is suddenly very close, and your hormones amplify everything.
Strategies that help:
- Talk openly with your partner about hopes, fears, and expectations for labor and the early postpartum days.
- Limit pregnancy and birth horror stories. Curate your social media. Other people's traumas are not predictions of yours.
- Practice relaxation techniques: deep breathing, visualization, gentle meditation. These will be useful in labor too.
- Sleep when you can. Use pillows for support, sleep on your left side when possible, and nap during the day if nighttime sleep is broken.
- Get help if you're struggling. Prenatal depression and anxiety are real and treatable. Tell your provider if you feel persistently low, hopeless, or panicky.
Common Concerns & When to Call Your Doctor
Call your provider or go to labor and delivery immediately if you experience any of the following:
- Decreased fetal movement (fewer than 10 movements in 2 hours during active time)
- Heavy vaginal bleeding (more than spotting)
- A sudden gush or steady trickle of fluid (possible water breaking)
- Regular contractions every 5 minutes or less for an hour
- Severe or persistent headache, vision changes, or upper abdominal pain (possible preeclampsia)
- Sudden severe swelling, especially in your face or hands
- Fever above 100.4°F (38°C)
- Burning during urination or pelvic pain (possible UTI)
Tests & Appointments This Week
From 36 weeks onward, prenatal visits typically occur weekly. At your 37-week appointment, expect:
- Blood pressure and weight check
- Urine screening for protein and glucose
- Fundal height measurement to track baby's growth
- Fetal heart rate monitoring
- Group B Strep (GBS) test results if testing was done at 36 weeks
- Cervical check (optional): Some providers check for dilation and effacement, but this isn't always necessary or predictive of when labor will start.
- Discussion of your birth plan, pain management options, and signs of labor
Tips for Week 37
- Finalize and install the car seat. Many hospitals will not discharge you without one. Consider having it inspected by a certified technician.
- Pack and double-check your hospital bag. Keep it by the door.
- Pre-register at the hospital. This saves valuable time when labor begins.
- Stock the freezer and pantry. Easy meals make the first weeks home much smoother.
- Confirm your support plan. Who will drive you to the hospital? Who will care for older children or pets?
Preparing for What's Next
The next two to three weeks could bring labor at any time. Make sure these items are ready:
- Newborn essentials: diapers (newborn and size 1), wipes, swaddles, onesies, a safe sleep space (bassinet or crib with firm mattress, no soft bedding)
- Feeding setup: if breastfeeding, a comfortable chair, nursing pads, lanolin; if formula feeding, bottles, formula, sterilizer
- Postpartum supplies for yourself: pads (maternity-size), peri bottle, comfortable underwear, nipple cream, comfortable loose clothing
- Pediatrician selected and first appointment scheduled (usually 2–5 days after discharge)
- Phone tree or notification list for sharing baby news
Frequently Asked Questions About Week 37
Is 37 weeks considered full term?
No. According to ACOG (American College of Obstetricians and Gynecologists), 37 weeks is classified as "early term," not full term. Full term begins at 39 weeks 0 days and ends at 40 weeks 6 days. Babies born at 37 weeks are generally healthy, but research shows they have slightly higher rates of respiratory issues, feeding difficulties, and NICU admission compared to babies born at 39+ weeks. Unless there is a medical reason, elective delivery before 39 weeks is not recommended.
Is it normal to feel intense pelvic pressure at 37 weeks?
Yes, this is very common and is often called "lightening." It happens when the baby drops lower into your pelvis in preparation for birth. You may notice it's easier to breathe (the baby is no longer pressing against your diaphragm) but harder to walk, and you'll likely urinate more often. Some people feel a sharp, shooting pain in the pelvis or vagina (sometimes called "lightning crotch") caused by the baby's position pressing on nerves. This is uncomfortable but not dangerous.
How can I tell the difference between Braxton Hicks and real labor at 37 weeks?
Braxton Hicks contractions are irregular, often go away when you change position or drink water, and don't get progressively stronger. True labor contractions become regular, get closer together over time (e.g., every 10 minutes, then every 7, then every 5), increase in intensity, and don't stop with rest or hydration. They typically start in the back and wrap around to the front. If you're unsure, time the contractions for an hour and call your provider if they're consistently 5 minutes apart or you're not sure.
When should I worry about decreased fetal movement at 37 weeks?
Movement patterns may feel different at 37 weeks because the baby has less room, but the frequency of movement should not decrease. Most providers recommend "kick counts" — feeling for 10 distinct movements within 2 hours during your baby's typical active time. If you don't feel 10 movements in 2 hours, or if movement feels significantly reduced compared to your baby's normal pattern, contact your provider or go to labor and delivery immediately. Reduced movement can be a sign of fetal distress.
Is it safe to have sex at 37 weeks pregnant?
For most low-risk pregnancies, yes. Sex does not cause labor in someone who isn't ready, and the baby is well-protected by the amniotic sac and cervical mucus plug. However, you should avoid sex if your provider has told you to (e.g., placenta previa, preterm labor risk, ruptured membranes, or active bleeding). Some couples find sex uncomfortable at this stage due to the baby's position and size — that's normal too.
What does it mean if I lose my mucus plug at 37 weeks?
Losing the mucus plug means your cervix is starting to change in preparation for labor. It may appear as a thick, jelly-like discharge that's clear, pink, or slightly bloody (sometimes called "bloody show"). Losing it doesn't mean labor is imminent — it could happen days or even weeks before labor begins. However, if you have heavy bright red bleeding (more than spotting), call your provider right away.
Should I be packing my hospital bag now?
Yes. By 37 weeks, your hospital bag should be packed and ready by the door. Babies can arrive any time from now on, and labor doesn't wait. Pack essentials for you (ID, insurance card, comfortable clothes for going home, toiletries, phone charger, snacks), for baby (going-home outfit, swaddle, car seat installed in the car), and your birth plan if you have one. Keep important phone numbers written down in case your phone dies.
Why am I so exhausted and emotional at 37 weeks?
Late pregnancy fatigue is real and is caused by a combination of carrying significant extra weight, poor sleep (frequent urination, discomfort, anxiety), hormonal shifts, and your body preparing for labor. Emotional swings are also driven by hormones (especially rising estrogen and prolactin) and the natural anticipation/anxiety about birth and parenthood. Rest as much as you can, accept help, and talk to your provider if mood symptoms feel overwhelming or you're having thoughts of harming yourself.
What is GBS testing and when does it happen?
Group B Streptococcus (GBS) is a bacteria that lives harmlessly in the vagina or rectum of about 25% of pregnant people but can be passed to the baby during birth and cause serious infection. The CDC and ACOG recommend universal GBS screening between 36 and 37 weeks via a vaginal/rectal swab. If positive, you'll receive IV antibiotics during labor to protect the baby. If you haven't been tested yet, ask your provider at your next visit.
Can I induce labor naturally at 37 weeks?
Most medical organizations strongly advise against attempting to induce labor before 39 weeks unless there is a medical reason, because babies born before 39 weeks have higher rates of complications. Methods like walking, sex, spicy food, and nipple stimulation are unlikely to work if your body isn't ready, and methods like castor oil or unprescribed herbs can be harmful. Be patient — your baby will come when ready. If induction is medically necessary, your provider will discuss safe options.
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