First Trimester
13 Weeks Pregnant
Fingerprints are forming—already unique!
🫛
Your baby is the size of a Peapod
7.4 cm
Crown-Rump Length
23 g
Approximate Weight
Week 1Week 13 — End of Trimester 1Week 27Week 42
🧒 Baby's Development This Week
During week 13, 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.
- Major organ systems are forming.
- Reflexes are developing.
- Facial features become more distinct.
- Bones are hardening.
- Nervous system matures.
🤰 Your Symptoms at Week 13
You are still in the early stages of your journey at week 13. 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.
Fatigue
Rest when possible.
moderate
Rest when possible.
moderate
Nausea
Eat small, frequent meals.
mild
Eat small, frequent meals.
mild
Breast tenderness
Wear a supportive bra.
mild
Wear a supportive bra.
mild
Frequent urination
Stay hydrated but limit evening fluids.
moderate
Stay hydrated but limit evening fluids.
moderate
Mood swings
Talk to your partner or friends.
mild
Talk to your partner or friends.
mild
Body Changes
- Uterus is expanding.
- Blood volume is increasing.
- Skin changes may occur.
When to Call Your Doctor
- Severe abdominal pain or cramping
- Heavy bleeding or spotting
- Severe dizziness or fainting
✅ Week 13 Checklist
- Take prenatal vitaminsEssential
- Drink plenty of waterEssential
- Eat a balanced dietRecommended
- Exercise moderatelyRecommended
- RestEssential
❓ Frequently Asked Questions
Is it normal to feel tired?
Yes, fatigue is very common.
What should I be eating?
A balanced diet with plenty of fruits and vegetables.
Can I exercise?
Yes, moderate exercise is generally safe and beneficial.
When will I feel the baby move?
Usually between 16 and 25 weeks.
How much weight should I gain?
It depends on your pre-pregnancy BMI. Ask your doctor.
👩⚕️
Reviewed by Dr. Sarah Johnson, OB/GYNLast reviewed May 2024
Sources
- American College of Obstetricians and Gynecologists (ACOG)
- Intergrowth-21st Fetal Growth Standards
⚕️ Medical Disclaimer: This content is reviewed by medical professionals but is for informational purposes only. Always consult your healthcare provider for personalized guidance about your pregnancy.