WEEK 4 / 40 · Trimester 1

Pregnancy Week 4

🌱 Size of a Poppy Seed

About 36 weeks until birth

Pregnancy week 4 baby size: Poppy Seed
🌱POPPY SEED

Length and weight values are given from week 7 onward.

Pregnancy hormones (hCG) are active! A home test may now show a positive result.

What's Happening With Your Baby This Week?

  • It has firmly attached to the uterine wall (implantation) and hCG hormone production has begun.
  • Cells are preparing to form the neural tube, which will become the brain and spinal cord; it will close over the coming weeks.
  • The cells that will form the heart and the first blood vessels are getting ready to take shape.
  • Three main layers (ectoderm, mesoderm, endoderm) are differentiating; each will form different organ systems.
  • The placenta and umbilical cord are beginning to form; these structures will be the baby's source of nutrients and oxygen.

This Week's Tips for Mom

  • Avoiding strenuous sports and high-impact activities is important during this period.
  • Supporting your vitamin D and iron levels under medical guidance can be beneficial.
  • Nausea and fatigue you may experience in the mornings are completely normal; your body is adjusting to hCG hormones.
  • Starting a prenatal vitamin would be wonderful; choose one containing folic acid, iron, and iodine.
  • You might consider scheduling your first doctor's appointment; blood tests and a general health assessment will be done.
Tip of the day: You'll typically need to wait until week 6 or 8 for the excitement of your first ultrasound. In the meantime, don't skip your folic acid supplement — neural tube closure happens during these weeks and folic acid plays a vital role in this process.
This content is for informational purposes only and is not a substitute for medical advice. Length and weight values are averages; every baby grows at their own pace.

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