38 Weeks Pregnant
At 38 weeks pregnant your baby is about 19 1/2 inches long and around 6 3/4 to 7 pounds, still early term and packing on fat for warmth. The brain is doing some of its most rapid growth right now, which is the main reason delivery is not scheduled before 39 weeks without a medical reason. Late-pregnancy symptoms — pelvic pressure, fatigue, aching hips — are doing real work this week.
Your week at a glance
| This week | Details |
|---|---|
| Baby size | About a leek, roughly 19 1/2 inches and 6 3/4 to 7 pounds (50 cm, 3.08 kg) |
| What is developing | Fat for warmth, lungs finishing surfactant, rapid brain growth, head-down with chin tucked |
| Your symptoms | Intense pelvic pressure, lightning crotch, aching hips, heartburn, broken sleep, mild swelling |
| To-do | Count kicks daily, line up childcare and pet care, confirm the route and the hospital plan |
How big is your baby at 38 weeks?
Your baby is still considered early term this week, the last week of the 37 to 38 weeks 6 days early-term window before full term begins at 39 weeks. They are about 19 1/2 inches long and around 6 3/4 to 7 pounds — roughly the size of a leek. The most important work happening this week is mostly invisible. Fat is still being laid down under the skin, smoothing out cheeks and arms and giving your baby the round, full look most newborns have. That fat will help your baby regulate body temperature in the outside world, which is a real challenge for a tiny new person. The lungs are still wrapping up surfactant production, the substance that keeps the air sacs from collapsing after birth.
The brain is doing some of its most rapid growth right now. At 38 weeks, your baby's brain is much closer to its full-term size than it was even two weeks ago, with neurons connecting and folds in the cerebral cortex deepening. This is the main reason ACOG and major US medical groups recommend against scheduling a non-medically indicated delivery before 39 weeks. Even one or two extra weeks in the uterus give the brain and lungs meaningful finishing time. Outside of brain and lungs, your baby's reflexes are sharp, the digestive system is ready for milk, and the kidneys are fully developed.
Most babies are now in a head-down (vertex) position, with their chin tucked to their chest, ready for birth. Space is tight, and movements likely feel like big rolls, stretches, and squirms rather than sharp jabs. Hiccups are common and feel like rhythmic little thumps low in your belly. You should still feel your baby move regularly every day. Pay attention to your baby's normal pattern and notice clear changes. If you feel a clear decrease, lie down on your left side, drink something cold, and count movements for an hour. If you do not feel 10 distinct movements in that hour, or if anything feels off, call your provider's office or labor and delivery line right away. Decreased movement should never wait until morning.
38 weeks pregnant symptoms
Your uterus reaches up nearly to your breastbone, your fundal height is around 38 centimeters, and the simple act of moving a 38-week belly around is exhausting. These are the common, normal things you may notice this week:
- Intense pelvic pressure — heavy and full between the legs, with the occasional sharp "lightning bolt" sensation called lightning crotch when your baby presses on a nerve
- Aching hips and pubic bone from the hormone relaxin loosening your ligaments and the weight pressing down
- Mild leg swelling, especially at the end of the day — but sudden, severe, or one-sided swelling needs a same-day call
- Frequent Braxton Hicks contractions that tighten the whole uterus and then completely release; real labor contractions get longer, stronger, and closer together no matter what you do
- Heartburn that doesn't quit, broken sleep, vivid dreams, more discharge, possible mucus plug loss, and possible colostrum leaking
Sleeping on your side with pillows tucked under your belly, between your knees, and behind your back can take a real edge off. Emotionally, this week often holds an unusual mix: deeply impatient, suddenly very nervous, occasionally moved to tears by something small, and frequently exhausted. All of that is normal. Be gentle with yourself, lower the bar on what counts as a productive day, and tell your partner what you actually need rather than hoping they guess. If you feel persistently low, panicky, or unable to enjoy anything for more than a few days, bring it up at your visit — screening for perinatal mood concerns is a routine, judgment-free part of US prenatal care.
Taking care of yourself this week
Rest is genuinely productive right now. Side-lying breaks during the day help reduce swelling and support blood flow to your baby. Build a sleep nest at night: a pillow between your knees, one supporting your belly, and one behind your back. Either side works, though many providers favor the left for circulation. If heartburn is keeping you up, prop your upper body slightly with extra pillows and avoid big meals in the few hours before bed. Keep movement gentle: walking, prenatal yoga, time on a birth ball with slow hip circles, side-lying stretches, and pelvic tilts all help with pelvic pressure and may encourage your baby to settle.
- Small, steady, nutrient-dense meals work better than three big ones — protein at every meal, plenty of vegetables and fruit, whole grains, and dairy or fortified plant alternatives.
- Steady water supports energy and reduces practice contractions.
- Skip herbal labor-induction remedies, including castor oil and many "natural" teas, unless your provider has specifically said yes.
- Avoid unpasteurized dairy, raw sprouts, high-mercury fish, deli meats unless steaming hot, and undercooked meat or eggs. Caffeine in small amounts (under about 200 mg a day) is fine.
One small step this week: confirm logistical plans for the day labor begins. Who will look after older children, including overnight if needed? Who will feed the dog or cat, water the plants, or pick up packages? Where are the car keys and the hospital bag? Save key contacts in your phone: provider's office, labor and delivery, pediatrician, insurance member services, and a backup ride. Walk through the route to the hospital with your partner during low-traffic and rush-hour times so the drive does not feel new in the middle of labor. Small moments of planning right now buy enormous calm later.
Appointments & tests
Your weekly visit this week will likely include the now-familiar checks: blood pressure, urine dip for protein and sugar, weight, fundal height (around 38 centimeters now), listening to your baby's heartbeat, and feeling your belly to check your baby's position. Most babies are head-down by this point. Some providers offer a cervical exam this week to feel whether your cervix is softening, thinning (effacement), or opening (dilation). A cervix at one or two centimeters does not mean labor is imminent, and a closed cervix does not mean labor is days or weeks away. Cervical exams are optional and you can decline.
This is a great visit to talk about your provider's approach to going past your due date. Most US practices begin antenatal testing around 41 weeks (often a nonstress test and a measurement of amniotic fluid), and many recommend induction by 41 weeks or before 42 weeks for safety reasons. ACOG also supports offering elective induction at 39 weeks for low-risk first pregnancies, since the research suggests it may modestly reduce the chance of cesarean delivery without increasing risk. Use this visit to confirm the practical pieces too: make sure hospital pre-registration is complete, your insurance is set up to cover delivery, and you have a clear plan for who to call when labor starts. Ask about visitor policies and the hospital's standard practices around skin-to-skin contact and delayed cord clamping (both are now considered evidence-based defaults).
Call your provider if
- A severe or persistent headache, vision changes, sudden swelling in your face or hands, or upper-right belly pain (possible preeclampsia)
- A clear decrease in your baby's movement compared to their normal pattern
- Any bright red vaginal bleeding heavier than a smear on toilet paper
- A sudden gush or steady trickle of fluid from your vagina (your water may have broken)
- Regular, rhythmic contractions — the 5-1-1 rule: every five minutes, lasting one minute, for at least one hour
- Heavy bleeding soaking a pad in an hour, fainting, a seizure, or no movement at all after lying on your left side for an hour — go to the ER or call 911
Reflects Mayo Clinic and Cleveland Clinic third-trimester fetal-development references and fetal-movement (kick count) guidance, 2024–2026.
Related questions
- How big is the baby at 38 weeks pregnant?
- About 19 1/2 inches long and around 6 3/4 to 7 pounds — roughly the size of a leek (about 50 cm and 3.08 kg). Fat is still being laid down to smooth out cheeks and arms and to help your baby regulate body temperature after birth.
- What are the signs of preeclampsia at 38 weeks?
- Call your provider right away for a severe or persistent headache that does not ease with rest, water, and acetaminophen; sudden swelling in your face or hands; vision changes such as spots, blurry patches, or flashing lights; pain in your upper right abdomen just under the ribs; or a sudden sharp increase in overall swelling. Untreated, preeclampsia can become dangerous fast — but caught early, it can be managed.
- Is 38 weeks full term?
- Not quite — 38 weeks is the last week of early term, the 37 to 38 weeks 6 days window before full term begins at 39 weeks. The brain is doing some of its most rapid growth right now, which is why ACOG and major US medical groups recommend against scheduling a non-medically indicated delivery before 39 weeks.
- What is lightning crotch at 38 weeks?
- It's a sharp "lightning bolt" sensation low between the legs when your baby presses on a nerve as pelvic pressure builds. It can feel intense but is usually harmless. Hips and the pubic bone often ache too as the hormone relaxin loosens your ligaments and the weight presses down.
Sources & further reading
ParentFlow: one free app, pregnancy to age six
ParentFlow follows your pregnancy week by week — baby size, what's developing, your symptoms, and the appointments and warning signs that matter — then becomes a free baby tracker for feeds, sleep, and growth after birth. Free on iPhone and Android.
App Store Google Play Open Web AppThis article reflects current ACOG, Mayo Clinic, Cleveland Clinic, CDC, and FDA guidance and is for educational purposes only. It does not constitute medical advice. ParentFlow is a wellness companion — not a substitute for your obstetric provider. For any medical concern, contact your healthcare provider.