First Trimester (Weeks 1–12)
Weeks 1–2: Preconception & Ovulation
- Body prepares for pregnancy
- Ovulation and fertilization occur
Please choose display type!
Week 3: Fertilization
- Sperm meets egg → zygote forms
- Cells begin to divide rapidly
Week 4: Implantation
- Blastocyst implants in the uterine lining
- Pregnancy hormones start rising
Week 5: Embryo Forms
- Neural tube (brain/spinal cord) begins forming
- Heart and circulatory system begin to develop
Week 6–7: Basic Structures Develop
- Heart starts beating
- Limb buds (arms/legs) form
- Facial features begin to show
Week 8: Organ Formation
- Major organs begin to develop
- Eyes, nose, and mouth become more defined
Week 9–10: Embryo Becomes Fetus
- All vital organs are formed
- Fingers, toes, and ears are visible
- Baby starts small movements
Week 11–12: First Trimester Ends
- Baby can open/close fists
- External genitalia begin forming
- Fingernails and bones start to harden
Second Trimester (Weeks 13–27)
Weeks 13–16: Growth Spurt
- Baby grows quickly in size
- Facial features are more distinct
- Baby can suck thumb
Week 17–20: Feel the Baby Move (Quickening)
- First gentle kicks may be felt
- Skin is covered with a fine hair (lanugo)
- Gender often visible on ultrasound
Week 21–24: Senses Develop
- Eyebrows and eyelashes form
- Baby can hear sounds and respond
- Lungs begin developing
Week 25–27: Stronger Movements
- Baby practices breathing
- Rapid brain growth
- Fat begins to build under skin
Third Trimester (Weeks 28–40)
Week 28–31: Baby is Viable
- Eyes can open and close
- Baby reacts to light and sound
- Begins storing minerals (iron, calcium)
Week 32–35: Maturing Organs
- Lungs continue to mature
- Movements are more forceful
- Baby begins to turn head-down
Week 36–37: Early Term
- Skin becomes smooth
- Baby practices sucking and grasping
- Head may begin engaging (dropping into pelvis)
Week 38–40: Full Term
- Baby is ready for birth
- Organs fully mature
- Weight: ~6–9 lbs; Length: ~18–21 inches
