25 weeks pregnant: baby, body and what to expect

Trimester 2 of 3About 6 months15 weeks to go

Week 25 of pregnancy: baby is about the size of a cauliflower

Week 25 at a glance

At 25 weeks, the baby is about 13.5 inches (34–35 cm) long and weighs around 1.5 pounds (660 g), roughly the size of a cauliflower. The spine and supporting structures are strengthening, and the baby can clench its fists and move more purposefully.

25 weeks pregnant is about 6 months. You are in month 6 of pregnancy and the second trimester.

Your baby at 25 weeks

Spine Strengthens and Fists Begin to Clench

At 25 weeks, an important development is happening: the spine and supporting structures are strengthening, and the baby can clench its fists.

What is happening this week

The baby is about 13.4 to 13.8 inches (34 to 35 cm) long and weighs around 1.5 pounds (660 g). Bones and muscles continue to strengthen, and the spine and supporting structures are becoming more stable.

The baby can clench its fists and may change hand position.
Movements are becoming stronger and more coordinated.
The brain, skin, and senses continue to mature.

Some ultrasounds at this stage can show clenched fists, body turns, and leg kicks. If the baby seems less active during a scan, this often reflects a normal sleep cycle. Ask your provider if you have questions about your baby's movement.

How this week may feel

In the second trimester, the baby's movements often become easier to notice. You may have heartburn, back pain, round ligament pain or pelvic pressure, or shortness of breath with activity.

Contact your provider right away if you have bleeding, fluid leaking from the vagina, severe pain, fever, regular painful contractions, or a noticeable decrease in movement after you have already been feeling the baby move.

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Your body at 25 weeks

Relief and Safe Exercises

Why Does Your Lower Back Hurt?

At 25 weeks, your baby is growing quickly, and your body is adjusting to the added weight. Many people notice back pain for these reasons: a shifting center of gravity, and the effects of relaxin, a hormone that loosens ligaments to prepare the body for birth.

Tips for Spinal Support

Watch your posture. Try not to over-arch your lower back when you stand.
Many people find a pregnancy pillow helpful for sleeping. Placing it between your knees may ease strain on your back and hips.
Choose supportive shoes with a low, stable heel. Avoid very high heels.

Gentle Exercises

Some people find that gentle strengthening of the core and pelvic floor helps support the extra weight of the growing bump. Many providers recommend asking about physical therapy or a prenatal exercise class for a plan that fits you.

Cat-Cow stretch: on your hands and knees, slowly round your back, then arch it gently.
Pelvic tilts: small movements of the pelvis that may ease tension in the lower back.
Upper back stretches: gentle stretches that may relieve muscle tightness and make it easier to sit upright.

Call your OB-GYN or midwife right away if you have severe or sharp back pain, pain that shoots down your leg, numbness, pain with fever, burning when you urinate, vaginal bleeding, fluid leaking from the vagina, or regular contractions.

Common symptoms at 25 weeks

Lower back pain

Many people feel an ache in the lower back as their posture shifts and the body loosens ligaments. Sitting with good lumbar support, bending at the knees, and gentle movement often help, and a provider can suggest safe options.

Leg cramps

Sudden calf cramps are common and can happen at night. Gently flexing the foot toward the shin, staying hydrated, and keeping up with daily walks may ease them for some people.

Heartburn

As the uterus grows, it can push on the stomach and cause burning in the chest. Smaller meals, staying upright after eating, and avoiding late-night snacks can help.

Shortness of breath

The growing uterus presses on the diaphragm, so a deeper breath may feel harder to take. Slowing down, sitting upright, and taking short rests can make breathing feel more comfortable.

Round ligament pain

Sharp or pulling pain on the sides of the belly or groin can happen when you stand up quickly or change position. Moving slowly and bending gently at the hips often eases it.

Constipation

Hormone changes and iron in prenatal vitamins can slow digestion. Drinking plenty of water, eating fiber from fruits, vegetables, and whole grains, and staying active may help keep things moving.

Your week 25 checklist

Schedule or confirm your glucose screening appointment if it has not happened yet. Drink water through the day and keep a bottle nearby. Set up a supportive pillow or chair for sleeping and sitting. Write down any questions about back pain, cramps, or breathing for your next visit. Check that your car seat is installed correctly and plan a time to learn how to use it. Plan short walks or gentle stretches you can do safely, after checking with your provider.

Tests and appointments

Glucose screening. A glucose challenge test, usually a sugary drink followed by a blood draw, is commonly offered between weeks 24 and 28 to check how your body handles sugar.
Complete blood count (CBC). A blood test that checks for anemia is often repeated around this time, and your provider may use the result to guide iron care.

For your partner: You can help by taking on heavier chores, carrying groceries, and offering a back rub or a pillow for support when your partner is sitting or resting. Going along to appointments and asking the provider about safe movement can also help you both feel more prepared.

Questions about week 25

How many months is 25 weeks pregnant?

25 weeks pregnant is about 6 months. You are in month 6 of pregnancy and the second trimester.

What trimester is 25 weeks?

Week 25 is in the second trimester. The first trimester runs through week 13, the second from week 14 to 27 and the third from week 28 until birth.

What is happening with the baby at 25 weeks?

At 25 weeks, the baby is about 13.5 inches (34–35 cm) long and weighs around 1.5 pounds (660 g), roughly the size of a cauliflower. The spine and supporting structures are strengthening, and the baby can clench its fists and move more purposefully.

Is back pain normal at 25 weeks?

Yes, back pain is common in the second trimester as posture changes and ligaments loosen. Many people find relief with supportive habits and gentle movement. Tell your provider if pain is severe, comes with fever, or is accompanied by leaking fluid or bleeding.

What is the glucose test like?

You drink a sweet orange-flavored drink, then have blood drawn about an hour later. Some providers use a longer fasting test instead. Your provider will explain what happens next if the result needs a follow-up.

Can I sleep on my back at 25 weeks?

Many providers suggest sleeping on your side, especially your left side, for comfort and blood flow. If you wake up on your back, that is generally okay. Pillows between your knees or under your belly may help you feel more comfortable.

Safe or not?

Ask your doctorCan I run while pregnant?Generally OKCan you eat salmon while pregnant?Generally OKIs decaf coffee safe during pregnancy?Generally OKCan I eat honey when pregnant?

Guides for this stage

Mental healthFeeling Less Attractive in Pregnancy: Learning to Accept a Changing Body Medical careCervical length check in pregnancy: what the test shows HealthManaging chronic conditions during pregnancy FeedingColostrum Leaking in the Second Trimester: What's Normal and What to Do

Coming up next weekWeek 26: The size of a zucchini: the baby may open its eyes for the first time, and they often look blueRead week 26 →

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Learn more

NIH: Pregnancy (NICHD)
CDC: Pregnancy

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General information only; it does not replace advice from your doctor or midwife.