At 38 weeks pregnant, your baby is about as long as a leek, and the lungs and brain are still fine-tuning ahead of birth. Two weeks (give or take) to go, and these final days matter more than they might seem.

If your dates feel confusing, remember that gestational age counts from the first day of your last period (LMP), not from conception — so "38 weeks pregnant" usually means about 36 weeks since ovulation. For the full timeline, see our pregnancy week-by-week guide, or find out exactly how your due date is calculated. If you're picking up from last week, catch up on 37 weeks pregnant first.

Diagram comparing a leek to a 38 week fetus, showing the lungs and brain still fine-tuning ahead of birth — At 38 weeks, your baby is about as long as a leek, with the lungs and brain still fine-tuning.

Key takeaways

Baby is about as long as a leek (roughly 49.8 cm, head to heel) and weighs around 3,083 grams.
The lungs, brain, and liver keep maturing through these final weeks, right up to birth.
About 2 weeks remain until a typical full-term due date.

What "38 Weeks Pregnant" Actually Means

Using standard gestational dating, week 38 starts about 36 weeks after ovulation, placing you in the second week of "early term." In fetal-age terms (counting from conception rather than your last period), this is closer to "36 weeks post-conception."

With roughly 2 weeks left until a typical 40-week due date, this is often when appointments include more direct conversations about labor signs and, if needed, induction timing.

Baby Size at 38 Weeks

At 38 weeks, your baby is about as long as a leek — roughly 49.8 centimeters, measured head to heel — and weighs around 3,083 grams. (Source: Baby Your Baby, Utah Department of Health)

Lungs and Brain, Still Fine-Tuning

Even now, your baby's brain, lungs, and liver are still developing important groundwork. Research summarized by the National Institutes of Health notes that a baby's brain at 35 weeks weighs only about two-thirds of what it will weigh at 39 to 40 weeks, and that these three organs undergo important development between 37 and 39 weeks specifically. (Source: NICHD, NIH)

This is a big part of why, absent a medical reason to deliver earlier, providers generally recommend waiting for labor to start on its own rather than scheduling an early delivery — babies born before 39 weeks face a meaningfully higher chance of complications like breathing or feeding difficulty. Your baby also continues gaining roughly half a pound a week at this stage, mostly as fat that helps with temperature regulation after birth. (Source: Cleveland Clinic)

Diagram showing a 38 week fetus with the lungs, brain, and liver continuing to mature ahead of birth — At 38 weeks, the lungs, brain, and liver continue important development right up until birth.

What You Might Notice at 38 Weeks Pregnant

Week 38 tends to bring a mix of a growing belly and the physical demands of late pregnancy. Here's what commonly shows up:

Stronger, more frequent Braxton Hicks contractions, which can sometimes be hard to distinguish from early labor.

Pelvic pressure or a feeling of heaviness, as your baby settles lower.

Trouble sleeping, as the belly grows large enough to limit comfortable positions.

Swelling in the feet and ankles, especially by the end of the day.

Backaches, as your center of gravity continues shifting forward.

Loose, more frequent bowel movements, which some people notice in the days before labor.

A burst of energy or restlessness, as the due date approaches.

It's also completely normal to have few or no symptoms yet. Symptom timing and intensity vary widely from person to person and even between pregnancies for the same person.

What's Happening in Your Body

The brain, lungs, and liver continue important development.
Fat continues building up, gaining roughly half a pound weekly.
Absent a medical reason to deliver sooner, waiting for labor to start on its own is generally recommended.
About 2 weeks remain until a typical full-term due date.

Tips for Week 38

Ask your provider directly about induction timing if it comes up, including the reasoning behind any recommendation.

Keep tracking your baby's movements, and report any noticeable decrease right away.

Rest when you can, even if restlessness makes it tempting to stay busy.

Keep taking your prenatal vitamin — steady nutrition continues to matter through the rest of pregnancy.

Double-check your hospital bag and birth plan one more time.

Tips for Partners

Keep your phone charged and your schedule flexible from here on out.
Help track fetal movement and contraction timing together.
Encourage rest, even during bursts of restless energy.
Confirm logistics one more time — route, parking, who to call, and in what order.

FAQ

How big is my baby at 38 weeks pregnant? About as long as a leek — roughly 49.8 centimeters, measured head to heel — and weighing around 3,083 grams.

Is my baby's brain fully developed at 38 weeks? Not quite. Research shows the brain, lungs, and liver continue important development between 37 and 39 weeks, with a 35-week brain weighing only about two-thirds of what it will weigh at 39 to 40 weeks.

Why do providers recommend waiting until 39 weeks if possible? Babies born before 39 weeks without a medical reason for earlier delivery have a meaningfully higher chance of complications, including breathing, temperature regulation, and feeding difficulties, since key organs are still maturing.

How much weight is my baby gaining now? Roughly half a pound per week at this stage, largely as fat that helps with temperature regulation after birth.

Why am I having more frequent bowel movements? Some people notice looser or more frequent bowel movements in the days before labor, though it's not a reliable predictor on its own.

What symptoms are normal at 38 weeks pregnant? Stronger Braxton Hicks contractions, pelvic pressure, trouble sleeping, swelling, backaches, and restlessness are all common at this stage.

How many weeks do I have left at 38 weeks pregnant? About 2 weeks remain until a typical 40-week due date, though labor can begin any time from here through 42 weeks and still be considered normal.

Pregnancy Checklist at Week 38

Keep taking a prenatal vitamin daily
Keep tracking your baby's movements daily
Double-check your hospital bag and birth plan
Discuss induction timing with your provider if relevant
Confirm logistics for getting to the hospital or birth center
Rest when you can, even with restless energy
Note any regular contractions, heavy bleeding, or reduced movement and call your provider if it occurs

Related guides

37 Weeks Pregnant: Symptoms, Baby Size & What to Expect — what happened the week before, as your baby reached early term
Pregnancy Week by Week: A Complete Guide — see what happens in every week and trimester, from implantation to full term
How Is Your Due Date Actually Calculated? — the exact formula behind your due date, plus a free calculator

Week 38 brings continued brain, lung, and liver development, with roughly 2 weeks left until a typical due date.