Week 33: Bones Hardening, Skull Staying Flexible
Your baby's bones are hardening throughout the body, though the skull bones remain deliberately flexible to ease passage through the birth canal.
Baby's Development
Most of your baby's bones are hardening now, except for the skull bones, which remain deliberately soft and flexible, with gaps (the fontanelles) that allow slight overlapping during birth to ease passage through the birth canal.
Your baby's immune system is developing, partly through antibodies received from you through the placenta, which will provide some early protection after birth.
Changes in Your Body
Your uterus is pushing up against your ribs for many women by this point, which can cause rib discomfort alongside the more familiar lower back and pelvic strain.
Common Symptoms
Common at 33 weeks:
- Rib discomfort
- Backaches
- Significant fatigue
- Swelling
- Shortness of breath
- Trouble sleeping
- Frequent urination
Nutrition This Week
Continue smaller, frequent meals if stomach capacity feels limited. Calcium remains important as your baby's bones continue hardening rapidly.
Safe Exercises
Gentle stretching can help ease rib and back discomfort. Avoid any movement that causes sharp pain, and discuss persistent rib pain with your doctor if it's significantly affecting your comfort.
Medical Checklist
This week:
- Review your birth plan once more and share copies with your support team
- Confirm transportation plans for when labor begins
- Continue daily movement awareness
Doctor Visit Guide
Your doctor will continue monitoring growth, position, and overall wellbeing. If you have any risk factors, additional monitoring like non-stress tests may begin around this time.