Fetal Development at 17–20 Weeks

Fetal Development at 17–20 Weeks

 Baby’s Development

  • Size: Baby is about the size of a sweet potato or banana, measuring 13–16.5 cm and weighing about 140–300 grams.
  • Kicks & Movements: You may start to feel baby’s movements, often described as flutters or “quickening.”
  • Skin & Hair:
  • - A creamy, white protective coating called vernix caseosa forms on the skin.
  • - The body is still covered in fine hair (lanugo) that helps retain warmth.
  • Heartbeat: Baby’s heartbeat can be clearly heard with a Doppler or at the anatomy scan.
  • Gender: External genitals are developed and may be visible on an ultrasound.
  • Limbs & Reflexes: Baby is more active—stretching, sucking, and swallowing. Reflexes like sucking and grasping are developing.
  • Hearing: The ears are functioning—baby can start hearing your voice, heartbeat, and external sounds.
  • Fat Formation: Baby starts building up brown fat to help with body temperature after birth.

What to Expect at This Stage

  • Anatomy Scan (usually around 18–20 weeks): A detailed ultrasound to check your baby’s development, growth, and organs.
  • Growing Bump: You’ll notice more obvious changes in your belly as the uterus expands.
  • Common Symptoms:
  • - Backaches or round ligament pain
  • - Mild swelling in ankles or feet
  • - Increased appetite
  • - Occasional shortness of breath or dizziness