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Trimester 1

5 Weeks Pregnant

During week 5, your baby is undergoing rapid organogenesis. Every day, millions of new cells are forming the foundations of the brain, heart, and limbs. They are safely tucked away in the amniotic sac, receiving all their nutrition through the developing umbilical cord.

8 min read Medically Reviewed Updated 2024-05-01
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Your baby is the size of a Sesame seed
0.3 cm
Length
0.2 g
Weight
Week 1Week 13 - End of Trimester 1Week 27Week 42

Baby's Development This Week

During week 5, your baby is undergoing rapid organogenesis. Every day, millions of new cells are forming the foundations of the brain, heart, and limbs. They are safely tucked away in the amniotic sac, receiving all their nutrition through the developing umbilical cord.

  • The heart begins beating, visible on early ultrasound.
  • Arm and leg buds start to appear.
  • The brain divides into its five main sections.
  • The circulatory system is the first organ system to function.

Your Symptoms at Week 5

You are still in the early stages of your journey at week 5. Your body is working overtime to produce the hormones needed to support the pregnancy, which can lead to symptoms like fatigue and nausea. It's important to prioritize rest and stay hydrated during this demanding time.

Morning sickness
Eat crackers before getting out of bed; try ginger tea. (moderate)
Fatigue
Nap when possible and go to bed earlier. (severe)
Frequent urination
Stay hydrated but reduce fluids before bedtime. (mild)
Breast tenderness
Wear a soft, wireless bra for comfort. (moderate)
Food aversions
Eat what appeals to you; avoid triggers. (mild)

When to Call Your Doctor

  • Severe nausea and vomiting (can't keep anything down for 24 hours)
  • Sharp or persistent abdominal pain
  • Bleeding heavier than spotting
  • Dizziness or fainting

Week 5 Checklist

  • Continue prenatal vitamins (essential)
  • Avoid raw/undercooked meats and eggs (essential)
  • Start a pregnancy journal or app (optional)
  • Research prenatal care providers if you haven't chosen one (recommended)

Frequently Asked Questions

Medical Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for personalized guidance about your pregnancy.