Third Trimester

Week 33: Your Baby is the Size of a Pineapple

You may develop a noticeable waddle as your pelvis loosens in preparation for birth. Your joints may feel looser due to the hormone relaxin. You might feel very warm as your metabolism is running at a higher rate. Sleeping comfortably is increasingly difficult.

Your baby at week 33

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Size of a Pineapple

Length: 43.7Weight: 1920
Week 1Week 33 of 40Week 40

Baby Development

The baby's bones are hardening, except for the skull bones, which remain soft and flexible for birth. The baby's immune system has been developing with antibodies passed from you through the placenta. The pupils can now constrict, dilate, and detect light entering the eyes. The baby is gaining weight rapidly - about 230 grams per week.

Week 33 Highlight: Your baby's skull bones remain soft and flexible, ready to mould during birth - nature's clever design for delivery!

Common Symptoms

Pelvic pressure
Waddling walk
Overheating
Difficulty sleeping
Joint pain
Itchy belly

Tips for Week 33

1

Stay cool and hydrated in warm weather.

2

Keep moving gently - walks and stretching help with discomfort.

3

Finalise baby name choices if you haven't already.

4

Make sure you know the signs of preterm labour.

South Africa Specific Info

Know the signs of preterm labour: regular contractions before 37 weeks, lower back pain, pressure in the pelvis, and a change in vaginal discharge. If you experience these, go to your nearest hospital immediately. In SA, call ER24 (084 124) or Netcare 911 (082 911) for emergency ambulance services, or go directly to your nearest hospital's maternity unit.

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Frequently Asked Questions

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About the Author

Due Date Calculator SA Editorial Team

Our content is reviewed by healthcare professionals familiar with South African maternal health practices. We combine evidence-based medical information with local knowledge to support South African mums throughout their pregnancy journey. Our team includes contributors with backgrounds in midwifery, obstetrics, and maternal health education.

Last reviewed: February 2026