Second trimester

Week 17 of Pregnancy

Fat begins to accumulate and the placenta is fully established.

Fetal size
Pear
Length
13 cm
Crown-rump (CRL)
Weight
140 g

Fetal development

  • Brown fat begins to accumulate in preparation for body temperature regulation.
  • Bones continue to harden.
  • Hearing becomes sensitive enough to react to loud sounds.

Maternal changes

  • The bump shifts your center of gravity, often causing lower back pain.
  • Mild swelling in the feet can begin.

Recommended checkups

  • Schedule the anatomy scan (the week 20 detailed ultrasound).

Jump to week

Textbook averages. Individual variation is wide and this is not medical advice — confirm with your OB.