Week 33: Bones Hardening
Your baby's bones are continuing to harden, except for the skull bones, which remain flexible for delivery. Baby is running out of room and movements may feel different.
Medically reviewed by Samantha L. Fox, RN, BSN, MSN
Nursing Informaticist · United States Navy Nurse Corps · Last reviewed
Your baby is the size of a...
🥒 Celery Bunch!
👶 Baby Development
- ✓Bones hardening (skull stays flexible for birth)
- ✓Immune system developing
- ✓Baby is running out of room — movements change from kicks to rolls
- ✓Pupils can constrict and dilate in response to light
- ✓Brain continues rapid growth
- ✓Baby is getting into a head-down position (if not already)
💊 Common Symptoms
- •Waddling walk — your gait changes
- •Pelvic pressure and discomfort
- •Braxton Hicks practice contractions
- •Insomnia and difficulty sleeping
- •Overheating and sweating
- •Tingling or numbness in hands (carpal tunnel)
🩺Clinical Context — From a Nurse's View
Most babies have rotated head-down by now or will in the next couple of weeks. About 3-4% remain breech at term. If yours is still breech at 36-37 weeks, your provider may offer external cephalic version (ECV) — manually turning the baby from outside the abdomen — which succeeds about 60% of the time. ECV is done in a hospital with continuous monitoring and IV access in case complications require an emergency C-section. The other major decision point in late pregnancy is the birth plan. Write what you want — pain management preferences, who's in the room, immediate skin-to-skin, delayed cord clamping (now standard, recommended by ACOG and AAP for healthy term babies for at least 30-60 seconds), feeding plan — but hold the plan loosely. Birth rarely follows the plan exactly, and flexibility is part of what makes for a positive experience. Discuss it with your provider and your support person.
Written by Samantha L. Fox, RN, BSN, MSN — Emergency Department nurse, US Navy Nurse Corps officer.
🚨 When to Call (or Go to the ER)
- !Regular contractions, fluid leak, bleeding — call
- !Decreased fetal movement — call
- !Severe headache, vision changes, RUQ pain — call
- !Calf pain/swelling on one side — call
✅ Normal — Even If It Feels Worrying
- ✓Waddling gait
- ✓Pelvic pressure
- ✓Insomnia
- ✓Overheating
✅ To-Do This Week
- Make sure you have newborn diapers and wipes stocked
- Prepare a postpartum recovery kit
- Discuss your birth plan with your partner in detail
- Set up a support system for the first weeks at home
- Learn about newborn jaundice and what to watch for
- Start perineal massage if you haven't begun
🩺 Questions for Your Doctor
- ?Is the baby in the correct position for delivery?
- ?How is my cervix — any signs of effacement or dilation?
- ?What are the signs of preeclampsia I should watch for?
- ?Is the baby's estimated weight normal for 33 weeks?
- ?When should I call or go to the hospital?
- ?What happens if the baby doesn't turn head-down?
📚 References
- [1]ACOG Practice Bulletin No. 222: Gestational Hypertension and Preeclampsia. Obstet Gynecol. 2020;135(6):e237-e260.
- [2]ACOG Practice Bulletin No. 234: Prediction and Prevention of Spontaneous Preterm Birth. Obstet Gynecol. 2021;138(2):e65-e90.
Editorial review: Samantha L. Fox, RN, BSN, MSN. Last reviewed: see footer.
Your baby is the size of a...