Pregnancy week 31: REM sleep visible
Baby experiencing REM sleep. Size of a coconut.
Where you are in pregnancy
You're in the third trimester. Most growth, baby preparing for birth.
What's happening to baby at week 31
Baby experiencing REM sleep. Size of a coconut. The full physical and neurological development happening this week is part of a continuous timeline — for the complete picture across all 40 weeks, see the complete pregnancy pillar.
What's happening to your body
Each pregnancy week brings physical changes. Common at week 31: hormonal shifts driving symptoms, blood volume changes, uterine growth (after week 12), or physical preparation for delivery (third trimester). Track symptoms in Wermom App for patterns.
- Continue prenatal vitamin (folic acid most important T1, iron throughout)
- Track symptoms and concerns for next OB visit
- Hydrate (pregnancy increases fluid needs by ~300mL/day)
- Begin or continue safe exercise (150 min/week target per ACOG)
- Mental health check-in
Red flags this week
Always call your provider for: heavy bleeding, severe one-sided pain, severe headache with visual changes, signs of preterm labor, sudden swelling, persistent severe vomiting, decreased fetal movement.
Track week 31 with Wermom App
Week-by-week guidance + symptom tracker + appointment reminders
Try Wermom App free