Week 25 of Pregnancy: Symptoms, Fetal Development, Risks and Essential Care

Week 25 of pregnancy marks an important stage in the second trimester—a week filled with rapid fetal development and significant physical changes in the mother. During this time, your baby weighs around 700 grams, measures nearly 32 centimeters, and begins to open their eyelids for the first time. Their brain is rapidly forming neural connections, their senses are becoming sharper, and their movements are more coordinated.

Meanwhile, the mother may experience shortness of breath, chest pressure, breast enlargement, increased vaginal discharge and mild swelling, all of which are considered normal at this stage. Understanding what changes are expected—and which signs require medical attention—helps ensure a healthier and more comfortable pregnancy.

In this guide, we’ll explore everything happening inside your body and your baby’s development during week 25, along with essential tips for nutrition, exercise, warning signs and medical care.

Fetal Development at Week 25

Weight and Length of the Baby

By week 25, your baby is growing rapidly:

Weight: 650–700 grams
Length: 31–33 cm from head to heel

The baby still looks slim because fat stores are just beginning to accumulate, but muscle tone and movement patterns are becoming stronger and more predictable.

Brain and Nervous System Development

This is one of the most crucial weeks for brain growth:

Deep grooves and folds (sulci and gyri) begin forming.
Billions of new neural connections are created.
The brain starts regulating basic functions such as breathing rhythms, temperature control and reflexes.

This neurological progress is essential for the baby’s survival after birth.

Vision, Hearing, and Opening of the Eyelids

A major milestone this week is the opening of the baby’s eyelids.

Your baby can now:

Detect bright lights through the uterus
Blink and open/close their eyes
React to sounds, especially your heartbeat and voice
Distinguish muffled noises from outside

This is the stage when babies start recognizing their mother’s voice.

Movement and Sleep Cycles

At week 25:

Your baby shows more organized sleep–wake cycles
REM sleep (active dreaming sleep) begins
Movements feel stronger and more rhythmic
The baby may respond to touch, sound and bright light

If fetal movements noticeably decrease, contact your healthcare provider.

Development of a Baby Girl at Week 25

If you’re carrying a girl, by this week:

Her ovaries contain millions of immature eggs
The uterus and fallopian tubes are fully formed
The external genitalia are now clearly visible on ultrasound

Growth patterns are otherwise identical to those of a baby boy.

Changes in the Mother’s Body at Week 25

Shortness of Breath

Shortness of breath is extremely common at 25 weeks.

Causes include:

The growing uterus pushing upward on the diaphragm
Increased oxygen demand
Elevated estrogen levels increasing breathing rate
Even more pronounced symptoms in twin or multiple pregnancies

Seek medical help if:

Shortness of breath is sudden or severe
It is accompanied by chest pain
You experience a racing heartbeat
You feel dizzy or faint

Breast Enlargement and Preparation for Breastfeeding

At this stage:

Milk-producing glands are growing rapidly
Breasts may feel heavy or tender
Prominent blue veins may appear
Some women may leak small amounts of colostrum

These changes are normal and indicate preparation for breastfeeding.

Chest Pressure and Rib Pain

Many women feel discomfort under the ribs due to:

The enlarged uterus pushing upward
Inflammation of the cartilage between the ribs
Poor posture or prolonged sitting

Tips to reduce rib pain:

Sit up straight with a pillow behind your lower back
Use warm compresses
Avoid tight clothing
Change positions frequently

Visible Veins and Skin Changes

During pregnancy, blood volume increases by about 40%, making veins more visible.

Common signs include:

Fine red or blue veins on the breasts and legs
Mild swelling in the legs and feet
Spider veins or varicose veins

Helpful tips:

Elevate your legs when resting
Avoid standing for long periods
Wear compression stockings if needed

Common Symptoms in Week 25

Normal Symptoms

Mild shortness of breath
Back and pelvic pain
Increased vaginal discharge
Swelling in the feet and ankles
Stronger and more frequent fetal movements
Heartburn and indigestion
Pressure under the ribs
Breast tenderness

These symptoms are usually harmless unless they become severe.

Warning Signs to Call Your Doctor About

These may indicate preterm labor or other complications:

Regular contractions every 10 minutes or less
Leakage of fluid from the vagina
Vaginal bleeding or spotting
Intense pelvic pressure
Severe back pain
Sudden decrease in fetal movements
Severe shortness of breath with chest pain
Blurry vision, severe headache, or sudden swelling

Seek medical help immediately if any of these occur.

Ultrasound at Week 25: What to Expect

Assessing Fetal Growth

Your provider will measure:

Head circumference (HC)
Abdominal circumference (AC)
Femur length (FL)
Estimated fetal weight (EFW)

These measurements help determine if the baby is growing appropriately.

Amniotic Fluid and Placenta Evaluation

The ultrasound also checks:

Amniotic fluid levels

Low fluid (oligohydramnios)
High fluid (polyhydramnios)

Placenta health and location

Anterior or posterior
Low-lying or placenta previa
Maturity and blood flow

Assessment of Brain, Heart and Organs

The ultrasound evaluates:

Brain structures
Heart function and heart rate (140–160 bpm)
Lung development
Kidney and liver size
Movement of the diaphragm

Screening for Preterm Labor Risk

If needed, a cervical length measurement is performed.

A cervix shorter than 25 mm increases the risk of preterm labor.

Shortness of Breath in Twin Pregnancy

Why It’s Worse in Twin Pregnancy

Rapid uterine growth
Greater pressure on the diaphragm
Higher blood volume
Increased oxygen demand
More pressure on lung space

When It’s Dangerous

Seek urgent care if you experience:

Sudden severe shortness of breath
Chest pain
Rapid heartbeat
Dizziness or fainting
Blue lips or fingers
Pain/swelling in one leg
Fever or productive cough

Ways to Reduce Breathlessness

Sit upright with good posture
Sleep with multiple pillows
Practice slow, deep breathing
Avoid overexertion
Drink enough water
Wear loose clothing

Preterm Labor at Week 25

Survival Rate of a Baby Born at 25 Weeks

With advanced NICU care, survival rates range from:

67% to 80%

This depends on:

Baby’s weight
Infection risk
Lung development
Whether it’s a twin pregnancy
Quality of NICU care

Signs of Preterm Labor

Regular contractions
Back pain that comes and goes
Pelvic pressure
Vaginal bleeding
Leaking fluid
Change in discharge
Reduced fetal movements

Preventing Preterm Labor

1. Progesterone Therapy

Reduces preterm birth risk by up to 33% in eligible women.

2. Reduced physical activity

Recommended when contractions or cervical shortening are present.

3. Cervical cerclage

Used earlier in pregnancy for a very short cervix.

4. Hydration

Dehydration can trigger contractions.

Steroid Injections for Fetal Lung Maturity

If preterm labor risk is high, betamethasone or dexamethasone is given to:

Improve lung function
Reduce respiratory distress
Lower risk of brain bleeding
Increase survival

Optimal effect occurs after 48 hours.

NICU Care for a 25-Week Baby

Babies born at this stage require:

Incubator (thermoregulation)
Ventilation or CPAP
IV nutrition
Infection monitoring
Continuous vital checks

Hospital stay may last weeks to months.

Twin or Multiple Pregnancy at Week 25

Common Symptoms

More severe shortness of breath
Faster weight gain
Fatigue
Increased swelling
Stronger fetal movements from multiple babies

Risks

Higher chance of preterm birth
Pre-eclampsia
Gestational diabetes
Iron-deficiency anemia
Growth restriction in one baby

Delivery in a Multiple Pregnancy

At week 25, if delivery occurs:

Cesarean section is usually required
Babies immediately enter the NICU
Higher risk of breathing problems and low birth weight

Nutrition and Weight Gain at Week 25

Calorie Needs

Single pregnancy: +300 calories/day

Twin pregnancy: +400–500 calories/day

Essential Nutrients

Protein: 75–100 g/day
Iron: to prevent anemia
Calcium: for bone development
Folic acid: for brain development
Omega-3 (DHA): for eye and brain growth

Foods to Limit

Raw or undercooked meat
Unpasteurized cheese
Processed meats
Excess caffeine (limit to 200 mg/day)
Sugary drinks

Healthy Weight Gain

Single pregnancy: 6–8 kg by week 25

Twin pregnancy: 9–13 kg by week 25

Exercise at Week 25

When Exercise Is Not Allowed

Preterm labor risk
Bleeding
Placenta previa
High blood pressure or preeclampsia
Ruptured membranes
Multiple pregnancy with complications

Safe Exercises

Walking
Swimming
Prenatal yoga
Light strength training
Breathing exercises

Benefits of Exercise

Easier labor
Less back pain
Better sleep
Improved energy

Prenatal Massage: Benefits and Safety

Benefits

Reduces back, neck and shoulder pain
Improves blood circulation
Relieves stress
Helps reduce swelling
Enhances sleep quality

When Massage Is Unsafe

High blood pressure
Preterm labor risk
Placenta previa
Severe swelling in one leg (possible clot)
Fever or infection

FAQ – Common Questions at Week 25

Is week 25 dangerous?

Not usually, unless symptoms of preterm labor or complications occur.

What is the normal fetal heart rate?

140–160 bpm.

Is reduced fetal movement normal?

Short resting periods are normal, but a noticeable decrease requires evaluation.

Can I travel?

Yes, if pregnancy is low-risk.

Is sex safe?

Yes, unless your provider has advised otherwise.

Conclusion

Week 25 of pregnancy is a time of remarkable growth and transformation—for both mother and baby. While many symptoms are natural and expected, understanding warning signs and maintaining proper nutrition, exercise and medical care will help ensure a healthier pregnancy. With continued monitoring and support, you are moving closer to meeting your little one.

Pregnancy