← Week 3
Week 5 →

Fetal Growth & Anatomical Milestones at Week 4

Your baby's development is an extraordinary biological sequence. At week 4, the embryo or fetus is hitting critical anatomical milestones as systems organize and prepare for life outside the womb.

Anatomical Benchmarks

At week 4, your baby is comparable in size to a Poppy Seed:

  • Crown-to-Heel Length: ~0.1 cm
  • Estimated Weight: ~<0.1 g
  • Trimester Phase: First Trimester

Developmental Highlights

Key anatomical systems developing this week include:

  • Nervous System: Synaptic links are forming, supporting reflex movements and coordination.
  • Musculoskeletal: Tiny cartilage models are solidifying into bone structure, and hands and feet refine.
  • Cardiovascular: Fetal circulatory pathways function, pumping oxygenated blood throughout the tiny body.

Download Gynosakhi to access beautiful 3D developmental visuals and track daily growth milestones.

← Week 3
Week 5 →

Get Daily Baby Developmental Milestones in Your Pocket

Download Gynosakhi to get 3D ultrasound visualizers, daily nutrition plans, and 24/7 AI obstetric assistance.