Week-by-Week Pregnancy Updates
Pregnancy is an incredible journey, filled with both excitement and curiosity. Understanding what’s happening in your body each week helps you prepare for the changes ahead. This week-by-week guide to pregnancy updates will walk you through every stage, from conception to delivery.
For more information on what to expect during pregnancy, check out What to Expect’s week-by-week guide.
First Trimester (Weeks 1–12)
The first trimester is when all the foundational work happens. Here’s how your baby grows in those initial weeks:
Weeks 1–2: Conception and Preparation
- Ovulation occurs, and fertilization follows within hours.
- Implantation of the fertilized egg begins.
- Focus on taking prenatal vitamins with folic acid to support healthy development.
Week 3–4: Embryo Formation
- The embryo starts dividing into layers that will form organs.
- Pregnancy hormones trigger the first signs, such as fatigue and nausea.
Weeks 5–8: Organ Development
- The neural tube, which becomes the brain and spine, closes.
- Vital organs like the heart, liver, and kidneys start forming.
- Limbs, facial features, and eyes begin to take shape.
Explore Mayo Clinic’s week-by-week fetal development for a detailed look at fetal development.
Weeks 9–12: Moving Toward the Second Trimester
- Reflexes develop, and the baby starts moving.
- Gender might be identifiable through advanced ultrasounds.
- The placenta fully develops to support the fetus.
Second Trimester (Weeks 13–26)
The second trimester is often called the “honeymoon phase” because many discomforts subside.
Weeks 13–16: Growth and Senses
- Bones harden, and the baby grows rapidly in size.
- Taste buds develop, and the baby begins swallowing amniotic fluid.
- Facial expressions and fingerprints form.
Weeks 17–20: Active Movements
- Your baby becomes more active, with movements you can feel.
- The nervous system develops further, enhancing sensory abilities.
Third Trimester (Weeks 27–40)
The third trimester focuses on preparation for birth.
Weeks 27–32: Gaining Strength
- The baby’s lungs and brain mature.
- Eyes open and respond to light.
- The fat accumulation helps regulate body temperature after birth.
Weeks 33–40: Final Preparation
- The baby moves into a head-down position.
- Lungs fully develop, and the baby gains significant weight.
- Labor signals such as contractions may begin.
Frequently Asked Questions (FAQs)
What happens if my baby is born early?
Babies born prematurely (before 37 weeks) may need extra care but can thrive with proper medical attention.
How accurate are due dates?
Due dates are estimates. Only about 5% of babies are born on their exact due date.
Can I feel my baby move in the first trimester?
Most first-time mothers feel movements between weeks 18–22, but it varies.
Tracking your pregnancy week by week helps you connect with your growing baby and ensures you stay informed about the changes in your body. Use this guide to navigate your journey confidently!