25 Weeks Pregnant
At 25 weeks pregnant your baby is about the size of a small cauliflower — roughly 13.5 inches and around 1 pound 7 ounces — and the nervous system is maturing quickly. A fatty coating called myelin is starting to wrap around nerve fibers, which is why kicks and rolls may feel more deliberate. Many babies are settling into early sleep cycles, and this is the window for the glucose screen.
Your week at a glance
| This week | Details |
|---|---|
| Baby size | About a small cauliflower, roughly 13.5 in and 1 lb 7 oz (about 660 g) |
| What is developing | Nerve myelin, sleep cycles, scalp hair, opening nostrils, fat filling in |
| Your symptoms | Harder sleep, heartburn, back pain, swollen ankles, leg cramps, hand tingling |
| To-do | Schedule the glucose screen, choose a pediatrician, keep calcium intake up |
How big is your baby at 25 weeks?
Your baby is about the size of a small cauliflower this week — roughly 13.5 inches from head to heel and around 1 pound 7 ounces (about 660 grams). The nervous system is maturing quickly. Nerve cells are growing longer and forming more connections, and a fatty coating called myelin is starting to wrap around nerve fibers, which makes signals travel faster and more reliably. That is why kicks and rolls may feel more deliberate and powerful right now. Fat continues to fill in steadily under the skin, giving your baby a rounder, less translucent look. The hair on the scalp is becoming visible and may even have some color and texture, though it can change a lot after birth.
Many babies start to settle into early wake-and-sleep cycles around now, alternating between quiet REM-like sleep, quiet non-REM sleep, and active wakeful periods. Those active periods can be unmistakable from the outside — your baby may push out a foot, do a slow roll, or hiccup rhythmically for ten or fifteen minutes at a time. The lungs are still working on producing surfactant, the substance that lets the air sacs open. The nostrils, which were plugged with tissue earlier in pregnancy, are starting to open back up, and your baby is rehearsing breathing-like movements (still on amniotic fluid, not air) more vigorously.
Your baby's other senses are sharp now too. They can clearly hear your voice and a partner's voice, and may settle or get more active at familiar sounds. Touch is well developed — your baby explores the umbilical cord, the walls of the uterus, and their own face and feet. Taste buds are mature enough to pick up on the flavors of whatever you eat as they pass into the amniotic fluid. This is a lovely week for partners to spend a few quiet minutes a day with a hand on the bump; you may not feel a kick every time, but when you do, that small, undeniable poke is one of the great early moments of becoming a family.
25 weeks pregnant symptoms
Sleep gets noticeably harder around now, and most of the week's symptoms gang up at bedtime. These are the common, normal ones this week:
- Harder sleep — the bump makes a comfortable position a project, heartburn flares when you lie down, and your bladder fills the moment you close your eyes
- Mild lower back pain that comes and goes, and occasional sciatica radiating down the back of a leg
- Swelling in the feet and ankles by evening, plus leg cramps at night
- Hand numbness or tingling (pregnancy carpal tunnel)
- Heartburn after meals, constipation, hemorrhoids, and varicose veins
- Mild shortness of breath, vivid dreams, and a stuffier nose
- Tight or itchy bump skin as stretch marks expand
A pregnancy pillow can feel like a luxury, but for many people it is the single thing that makes nighttime workable. Emotionally, the third trimester is just around the corner, and many people alternate between excitement and pre-labor jitters. If anxiety, low mood, or sleep trouble is wearing you down, bring it up at your next visit — perinatal mental-health support is effective and common.
Taking care of yourself this week
For lower-back and pelvic discomfort, side-sleeping with a pillow setup is the simplest fix. Tuck a pillow between your knees, another behind your back, and a small one under the bump; a U-shaped pregnancy pillow pulls it all together, and you should avoid lying flat on your back. During the day, mind your posture — soft knees, weight balanced on both feet, shoulders relaxed — and get up to walk every 30 to 45 minutes. Skip high-impact or jerky activities, but stick with walking, prenatal yoga, swimming, and stationary cycling.
- For swollen legs, try compression socks, put your feet up when you sit, and hydrate steadily — aim for around 80 to 100 ounces of water a day.
- Keep calcium intake high (around 1,000 mg a day): pasteurized milk, yogurt, cottage cheese; fortified plant milks and orange juice; canned salmon and sardines with bones; firm tofu; and dark leafy greens.
- Pair calcium-rich foods with vitamin D for better absorption, and try not to take iron and calcium supplements at the same time.
- Choose a pediatrician — schedule a few free meet-and-greets and bring questions about hours, after-hours coverage, insurance, and distance from home.
- Finish a few practical tasks — register for an infant CPR class, sort out maternity-leave paperwork, and schedule a car-seat installation check at a fire station.
The third trimester moves quickly, so getting these done now is a gift to your future, more tired self.
Appointments & tests
Week 25 sits squarely inside the recommended window for the gestational diabetes glucose challenge test, which ACOG recommends between weeks 24 and 28. If yours has not been scheduled, call your provider's office. The one-hour test involves drinking a sweet 50-gram glucose drink at the clinic, waiting an hour, then having a single blood draw — no fasting required. If that number is elevated, a longer three-hour test confirms whether you have gestational diabetes; many positive one-hour screens do not turn into a diagnosis. If diagnosed, it is very manageable with diet, blood-sugar monitoring, and occasionally medication, and it usually resolves after birth.
If you have a regular prenatal visit this week, expect the standard routine: a check of your blood pressure, weight, and urine; a listen to your baby's heartbeat; a measurement of your fundal height (around 23 to 27 centimeters at this point); and time to talk through any new symptoms. Your provider may draw a complete blood count to recheck for anemia, since iron needs are climbing. If you are Rh-negative, you will hear more about RhoGAM — a routine injection given around 28 weeks. Your provider may also start talking about the Tdap vaccine, recommended every pregnancy between weeks 27 and 36.
For pregnancies that are being more closely monitored — twins, a history of preterm birth, gestational hypertension, prior preeclampsia, or growth concerns — surveillance may step up around now, including cervical-length checks, growth ultrasounds, and more frequent visits. Helpful questions at this stage: "When is my glucose screen?" "How is my iron looking?" "When will I get Tdap, the flu shot, RhoGAM, and the RSV vaccine in season?" "What signs of preterm labor should I watch for?" Write the answers down.
Call your provider if
- A fever above 100.4°F, especially if it does not come down with rest and fluids
- Foul-smelling or unusually colored vaginal discharge, or severe, persistent abdominal pain
- Regular, painful contractions (more than four to six in an hour), low backache that comes in waves, or new constant pelvic pressure
- A sudden gush or steady trickle of clear fluid, or any bleeding beyond very light spotting
- A severe persistent headache, sudden visual changes, severe upper-belly pain on the right, sudden facial or hand swelling, burning with urination, persistent vomiting, intense itching of palms and soles, or a sustained decrease in your baby's usual movements
Reflects Mayo Clinic and Cleveland Clinic second-trimester fetal-development references and Mayo Clinic fundal-height guidance, 2024–2026.
Related questions
- How big is the baby at 25 weeks pregnant?
- About the size of a small cauliflower — roughly 13.5 inches from head to heel and around 1 pound 7 ounces (about 660 grams). Fat is filling in steadily, giving your baby a rounder, less translucent look.
- Does the baby have sleep cycles at 25 weeks?
- Many babies start to settle into early wake-and-sleep cycles around now, alternating between quiet REM-like sleep, quiet non-REM sleep, and active wakeful periods. Active periods can be unmistakable from the outside — a foot pushing out, a slow roll, or rhythmic hiccups for ten or fifteen minutes.
- When is the glucose screening test in pregnancy?
- Week 25 sits inside the recommended window for the gestational diabetes glucose challenge test, which ACOG recommends between weeks 24 and 28. The one-hour test involves drinking a 50-gram glucose drink, waiting an hour, then a single blood draw. No fasting is required.
- Why is sleep so hard at 25 weeks pregnant?
- The bump is large enough to make finding a comfortable position a small project, heartburn often flares when you lie down, and your bladder seems to fill the moment you close your eyes. Side-sleep with a pillow between your knees and another behind your back, prop your upper body up a few inches, and avoid large amounts of fluid in the last two hours before bed.
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.