At 26 weeks pregnant, your baby is about the size of a scallion, and starting to make melanin — the pigment that will eventually determine skin, hair, and eye color. The lungs are also starting to produce surfactant this week, a key substance that helps keep tiny air sacs from collapsing once breathing begins.

If your dates feel confusing, remember that gestational age counts from the first day of your last period (LMP), not from conception — so "26 weeks pregnant" usually means about 24 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 25 weeks pregnant first.

Diagram comparing a scallion to a 26 week fetus, showing melanin production and lungs starting to produce surfactant — At 26 weeks, your baby is about the size of a scallion, with melanin production starting and lungs beginning to make surfactant.

Key takeaways

Baby is about the size of a scallion (roughly 35.6 cm, head to heel) and weighs around 760 grams.
Melanin production begins, which will influence skin, hair, and eye color.
The lungs start producing surfactant, an important substance for breathing after birth.

What "26 Weeks Pregnant" Actually Means

Using standard gestational dating, week 26 starts about 24 weeks after ovulation, placing you right near the boundary of the second and third trimesters. In fetal-age terms (counting from conception rather than your last period), this is closer to "24 weeks post-conception."

This week is also commonly when gestational diabetes screening happens for a lot of people, since many providers schedule it somewhere in the weeks 24-to-28 window.

Baby Size at 26 Weeks

At 26 weeks, your baby is about the size of a scallion — roughly 35.6 centimeters long, measured head to heel, and weighing around 760 grams. (Source: Baby Your Baby, Utah Department of Health)

Melanin, Surfactant, and Screening for Gestational Diabetes

This week brings two meaningful developments: your baby's body starts making melanin, and the lungs begin producing surfactant. (Source: Cleveland Clinic) Melanin production is the starting point for eventual skin, hair, and eye pigmentation, though the final shade often continues developing well after birth. Surfactant, meanwhile, is a substance that coats the inside of the tiny air sacs in the lungs, keeping them from collapsing once your baby starts breathing air instead of amniotic fluid.

If your provider hasn't scheduled it already, this is a common week for gestational diabetes screening, which usually happens sometime between weeks 24 and 28. Our guide to gestational diabetes covers what the test involves and what a diagnosis would mean for the rest of your pregnancy.

Diagram showing a 26 week fetus with melanin pigment cells developing in the skin and surfactant forming in the lungs — At 26 weeks, melanin production begins in the skin, and the lungs start producing surfactant.

What You Might Notice at 26 Weeks Pregnant

Week 26 tends to bring a mix of screening appointments and familiar late-second-trimester symptoms. Here's what commonly shows up:

Shortness of breath, as the growing uterus starts to press up against the diaphragm.

Carpal tunnel-like tingling, which can show up in the hands and wrists as fluid retention increases.

Braxton Hicks contractions, appearing as occasional, painless tightening in the belly.

Backaches, as your center of gravity continues shifting forward.

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

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

Leg cramps, particularly at night, which remain common for some people at this stage.

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

Melanin production begins, the starting point for skin, hair, and eye pigmentation.
The lungs start producing surfactant, key for breathing after birth.
Gestational diabetes screening often happens around now, within the 24-to-28 week window.
Shortness of breath may increase as the uterus presses on the diaphragm.
Fluid retention can bring on carpal tunnel-like tingling in the hands and wrists.

Tips for Week 26

Schedule your glucose screening if you haven't already, and ask your provider any questions beforehand.

Sit and stand up slowly if shortness of breath or lightheadedness shows up.

Try wrist stretches or a brace at night if tingling in the hands is bothering you.

Stay hydrated and stretch calves before bed if leg cramps are an issue.

Elevate your feet in the evening if mild swelling shows up.

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

Tips for Partners

Offer to come along to the glucose screening — the waiting period can take a while, and company helps.
Watch for signs of shortness of breath, and encourage rest breaks during activity.
Help with tasks that require a strong grip, like opening jars, if wrist tingling is an issue.
Keep track of appointments together, since this stretch of pregnancy often has more of them.

FAQ

How big is my baby at 26 weeks pregnant? About the size of a scallion — roughly 35.6 centimeters long, measured head to heel, and weighing around 760 grams.

What does melanin production mean for my baby's appearance? It's the starting point for skin, hair, and eye pigmentation, though the final color often continues to develop and shift well after birth.

What is surfactant, and why does it matter? Surfactant coats the tiny air sacs in the lungs, keeping them from collapsing once your baby starts breathing air after birth.

When does gestational diabetes screening usually happen? Most providers screen sometime between weeks 24 and 28, often around week 26 or 27 for a lot of people.

Why am I short of breath more often now? As the uterus grows and presses upward on the diaphragm, it can reduce the amount of room your lungs have to expand fully.

What symptoms are normal at 26 weeks pregnant? Shortness of breath, carpal tunnel-like tingling, Braxton Hicks contractions, backaches, swelling, trouble sleeping, and leg cramps are all common at this stage.

Is carpal tunnel syndrome common during pregnancy? Tingling or numbness in the hands and wrists can happen as fluid retention increases pressure on nerves, and it typically improves after delivery.

Pregnancy Checklist at Week 26

Keep taking a prenatal vitamin daily
Schedule your gestational diabetes screening if you haven't already
Try wrist stretches if hand or wrist tingling shows up
Stay hydrated and stretch before bed if leg cramps are an issue
Elevate your feet if mild swelling shows up
Sit and stand up slowly if shortness of breath or lightheadedness occurs
Note any severe cramping, heavy bleeding, or reduced movement and call your provider if it occurs

Related guides

25 Weeks Pregnant: Symptoms, Baby Size & What to Expect — what happened the week before, as hair and body fat continued developing
Gestational Diabetes: What You Need to Know — what the screening involves and what a diagnosis means
Pregnancy Week by Week: A Complete Guide — see what happens in every week and trimester, from implantation to full term

Week 26 brings two meaningful milestones — melanin production beginning and surfactant forming in the lungs — right around the time many people have their gestational diabetes screening.