Week 29: Baby's Brain Booming
Your baby's brain is growing at an incredible rate, developing billions of neurons. The head is getting bigger to accommodate this rapid brain growth.
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...
🎃 Butternut Squash!
👶 Baby Development
- ✓Brain developing billions of neurons
- ✓Head growing larger for the rapidly expanding brain
- ✓Muscles and lungs continue to mature
- ✓Bones are fully developed but still soft
- ✓Baby can regulate their own body temperature somewhat
- ✓Fat layer continues to build
💊 Common Symptoms
- •Varicose veins may worsen
- •Hemorrhoids
- •Heartburn and reflux
- •Trouble sleeping
- •Frequent urination day and night
- •Feeling large and uncomfortable
🩺Clinical Context — From a Nurse's View
Iron-deficiency anemia is common in the third trimester — your blood volume has expanded ~45% but your red cell mass only ~25%, creating a relative dilution. Add baby's escalating demand for iron to build their own stores and many people drop their hemoglobin enough to need supplemental iron beyond the prenatal vitamin. Symptoms — exhaustion beyond what you'd expect, breathlessness on minimal exertion, restless legs, ice cravings (pagophagia, a form of pica) — all earn a CBC and ferritin recheck. Constipation from iron supplements is the most common reason people stop taking them; pair with a stool softener and increase fiber if needed. Varicose veins worsen now from venous pressure; compression stockings (graduated 20-30 mmHg, prescribed if covered) help. Don't sit cross-legged for long stretches.
Written by Samantha L. Fox, RN, BSN, MSN — Emergency Department nurse, US Navy Nurse Corps officer.
🚨 When to Call (or Go to the ER)
- !Decreased fetal movement — call
- !Severe headache, vision changes, RUQ pain, swelling — call
- !Calf pain, swelling, redness in one leg — call (rule out DVT)
- !Regular contractions, fluid leak, bleeding — call
✅ Normal — Even If It Feels Worrying
- ✓Worsening varicose veins
- ✓Hemorrhoids
- ✓Heartburn most evenings
- ✓Frequent night urination
✅ To-Do This Week
- Start doing perineal massage to prepare for delivery
- Practice breathing techniques for labor
- Finalize baby's name (if you haven't already)
- Set up the diaper changing station
- Stock up on postpartum pads and supplies
- Arrange for pet care during delivery if needed
🩺 Questions for Your Doctor
- ?Is the baby's brain development on track?
- ?How can I manage varicose veins?
- ?When should the baby be head-down?
- ?What positions can help turn a breech baby?
- ?Is it safe to have sex during the third trimester?
- ?When should I start maternity leave?
📚 References
- [1]ACOG Committee Opinion No. 762: Prepregnancy Counseling. Obstet Gynecol. 2019;133(1):e78-e89.
- [2]ACOG Practice Bulletin No. 229: Antepartum Fetal Surveillance. Obstet Gynecol. 2021;137(6):e116-e127.
Editorial review: Samantha L. Fox, RN, BSN, MSN. Last reviewed: see footer.
Your baby is the size of a...