How to Prepare Your Body in the Third Trimester of Pregnancy

Practical, Evidence-Based Guidance for Birth Preparation

The third trimester is when pregnancy starts to feel very real. The baby is growing rapidly, the body feels heavier, and thoughts often turn toward labour, birth, and recovery.

Across Tunbridge Wells, Kent, and Sussex, we regularly support women in the third trimester who feel a mix of excitement and uncertainty, wondering what they should be focusing on now, what’s normal, and how to prepare their bodies without overdoing it.

The third trimester is not about “training harder”. It’s about supporting adaptability, comfort, and confidence as your body prepares for birth.

What’s Happening in the Third Trimester?

During the third trimester:

• Baby gains significant weight and size
• The uterus places increasing demand on posture and balance
• The rib cage and breathing system adapt further
• The pelvis, sacrum, and pelvic floor begin preparing for labour

Energy levels may fluctuate, and movement can feel more effortful, even for those who felt great earlier in pregnancy.This stage is less about building capacity, and more about working with change rather than against it.

What’s Normal in the Third Trimester (And What Often Surprises People)

Common and Normal Experiences

Many women notice:

• Increased fatigue or slower recovery
• Pelvic, hip, or lower back discomfort
• Rib or upper back tightness
• Heaviness or pressure in the pelvis
• Reduced tolerance for prolonged standing or walking
• Sleep disruption

These changes reflect the physical demands of late pregnancy, not failure or lack of fitness.

When Extra Support May Be Helpful

Consider seeking guidance if you experience:

• Pelvic girdle pain (PGP) affecting daily movement
• Pain when rolling in bed or standing on one leg
• Persistent rib pain or breath restriction
• A feeling of pelvic tension or difficulty relaxing
• Back, neck, rib shoulder or leg discomfort
• Needing to significantly reduce activity due to pain

Support at this stage can make a meaningful difference to both comfort and birth preparation.

Posture and Movement in the Third Trimester

As the centre of mass shifts further forward, posture adapts again.

Common third-trimester patterns include:

• Increased lumbar extension
• Rib cage flaring or lifting
• Reduced hip extension during walking
• Increased pelvic floor load

Rather than trying to “correct” posture, the goal is to:

• Reduce unnecessary strain
• Support efficient movement
• Preserve comfort and confidence

Small adjustments in how you sit, stand, roll, and walk can significantly reduce discomfort.

Exercise and Movement in the Third Trimester

Movement remains important in late pregnancy — but it often looks different from earlier trimesters.

The aim now is to:

• Maintain mobility
• Support circulation
• Reduce stiffness and discomfort
• Prepare the body for labour positions

Helpful movement often includes:

• Walking at a comfortable, variable pace
• Gentle hip, pelvic, and spinal mobility
• Low-load strength or resistance exercises you’re already familiar with
• Supported squats, lunges, or all-fours positions
• Regular position changes throughout the day

For those who exercised earlier in pregnancy, continuing familiar movement is usually appropriate when adapted to comfort and energy levels. The focus shifts from fitness to function and ease of movement.

Gentle Third Trimester Movement Checklist

• Comfortable walking or gentle daily movement
• Pelvic tilts and circles
• Hip opening and supported mobility work
• Light strength or resistance exercises as tolerated
• Frequent rest and position changes

Be cautious with:

• Pushing through pain or pressure
• Breath holding during effort
• Prolonged static positions
• Fatigue that lingers after activity

In the third trimester, effective movement is about staying strong and mobile with the right support.

Breathing and Pelvic Floor Preparation for Birth

As birth approaches, breathing and pelvic floor coordination become increasingly important.

Helpful focus areas include:

• Maintaining rib cage mobility for efficient breathing
• Allowing the pelvic floor to fully relax and lengthen
• Avoiding constant pelvic floor “holding”
• Practising breathing in a variety of positions

Breathing in late pregnancy is less about technique and more about:

• Rhythm
• Relaxation
• Responsiveness

These elements support both labour and early postnatal recovery.

Why Mobility Matters Most in the Third Trimester

Mobility of the:

• Hips
• Pelvis and sacrum
• Lower lumbar spine
• Thoracic spine and rib cage

…supports the body’s ability to adapt during labour.

Maintaining comfortable movement in these areas may:

• Support pelvic outlet opening
• Reduce unnecessary tension
• Improve tolerance of labour positions
• Support pelvic floor relaxation

Mobility and coordination become even more important

As birth approaches, the body needs to adapt the shape of the pelvis, allow the sacrum and coccyx to move freely, coordinate breathing with pelvic floor relaxation, and transition easily between labour positions. Maintaining mobility, coordination and functional strength helps support these processes by providing stability, endurance, and confidence in movement.

When to Seek Pregnancy Osteopathy in the Third Trimester

Pregnancy osteopathy may be particularly helpful in the third trimester if:

• Pain is limiting daily activity
• You’re experiencing pelvic girdle pain or musculoskeletal discomfort
• Breathing feels restricted or uncomfortable
• You want guidance preparing your body for labour
• You’re thinking ahead to postnatal recovery

Care at this stage is gentle, supportive, and tailored to your comfort and gestational stage.

Third Trimester Pregnancy Support in Tunbridge Wells, Kent

At One Health Osteopathy Clinic, we regularly support women throughout the third trimester of pregnancy.

Our osteopaths are:

• Trained to Master’s level
• Experienced in supporting women throughout pregnancy, birth preparation, and postnatal recovery
• We also specialise in paediatric osteopathy, offering gentle, evidence-informed care for babies, children, and teenagers from birth through to adolescence.

In addition, we have an osteopath with postgraduate specialist training in women’s health osteopathy, pregnancy, scar therapy using Lymphatouch for C-sections, and the Mummy MOT postnatal check.

Pregnancy MOTs and Birth Preparation

The third trimester is an ideal time to book a Pregnancy MOT, particularly between 32–36 weeks.

A Pregnancy MOT can help:

• Assess posture, mobility, breathing, and pelvic floor coordination
• Identify areas that may benefit from support before birth
• Provide personalised guidance for labour positions
• Plan for early postnatal recovery

We also offer new patient osteopathy consultations for women during pregnancy who are seeking support at any stage for musculoskeletal pain or discomfort.

We have a separate Pregnancy MOT service page with full details.
Osteopathy for Pregnancy

Final Thought

The third trimester is not about doing more, it’s about doing what supports you best.

Preparing your body at this stage means:

• Respecting physical limits
• Supporting mobility and breathing
• Reducing unnecessary tension
• Building confidence for birth

With the right guidance, the final weeks of pregnancy can feel supportive, intentional, and calm, rather than overwhelming.

This whole-body approach to pregnancy and postnatal care reflects the principles we explore in our blog on pregnancy mobility and birth preparation, which explains how hip, pelvic, spinal, and rib mobility work alongside strength and coordination to support labour and recovery.

As you approach birth, you may find it helpful to explore our related blogs on Preparing Your Body for Birth: Why Hip, Pelvic, Spinal, and Rib Mobility Matters in Pregnancy, Breathing for Labour: Why It’s Not About “Deep Breaths”, Pelvic Floor Myths in Pregnancy: What Really Supports Your Body for Birth and Recovery, and The Fourth Trimester: How to Support Your Body in the First Six Weeks After Birth, which together offer practical, evidence-based guidance for labour and early recovery.