Third Trimester
Week 30: Baby can regulate their own body temperature now.
Here's everything happening with your baby and your body this week.
Your baby is the size of a
Cabbage
Length
15.7 in
Weight
1.32 kg
Week
30 / 40
💡 Expert tip
Pelvic floor exercises (Kegels) now and throughout the third trimester significantly reduce incontinence and support recovery.
🌱 Baby's development this week
- Body temperature regulation beginning
- Lanugo (fine hair) disappearing as fat increases
- Red blood cells now produced entirely by bone marrow
- Brain development accelerating dramatically
Science fact
At 30 weeks, the fetal brain begins producing cortisol in response to stress — the earliest evidence of a stress response system. This is why maternal stress management directly benefits fetal neurodevelopment.
🤰 Your symptoms this week
Stress incontinence
leaking urine when sneezing; Kegels reduce this significantly
Braxton Hicks intensifying
time them; regular contractions before 37 weeks need medical attention
Practice contractions — normal from mid-pregnancy. Stay hydrated, change position, rest.
Fatigue returning
third trimester is physically demanding; rest without guilt
Rest when you can — your body is building a placenta. Iron-rich foods (spinach, lentils) help. Short walks boost energy.
💛 Changes in your body
- Braxton Hicks may feel intense — usually irregular and painless
- Leaking urine when sneezing/coughing (stress incontinence) common
- Sleeping 8+ hours with frequent interruptions
- Significant fatigue returning
💙 Mental health this week
Sleep deprivation from late pregnancy is both preparation and practice for the newborn period. This is not comforting, but understanding it
🥗 Nutrition focus
- Magnesium glycinate (300–400mg before bed) reduces leg cramps, improves sleep, and supports muscle function
- Continue prenatal vitamin — even when appetite drops in late pregnancy
- Herbal teas to avoid: pennyroyal, black cohosh, blue cohosh — all can stimulate contractions
📅 Appointment / test
Discuss group B strep (GBS) test timing — usually 35–37 weeks. GBS positive means IV antibiotics in labor (routine and effective).
✅ This week's checklist
Continue pelvic floor exercises — 3x daily minimum
Prepare a rough birth plan and share with your support person
Research newborn feeding (breastfeeding prep, formula options) to reduce postpartum stress
Track your pregnancy week by week
Interactive guide · 40 weeks · Fruit size visualizations · Personalized tips
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