Week 9 to 10

Growth spurt, nails, and fingerprints

Human Prenatal Age
  • PCW 10
  • Days 63-69
  • Gestational Week 12
  • The fetus’s heart has beat over 10 million times already!1

  • All of the intestines, which grew so fast that they extended outside the embryo, just under the umbilical cord, are back in the abdomen.2 

  • The fetus’s body weight increases by over 75%.3

This week, the unborn child’s fingernails start to grow.  Just like an adult’s, the fetus’s nails grow out slowly from the nail bed. The fingernails won’t reach the fingertips until approximately 30 weeks after conception.4 The toenails start growing at 14 weeks after conception and finish growing by 34 weeks after conception.5

This image shows a real living fetus in the womb, recorded using fetoscopy. The nerve receptors on the face, hands, and feet of this fetus respond to light touch. If something touches the sole of her feet, she will curl her toes. Also notice how much her arms and legs have grown from the previous week. (Image Credit: The Center for Bio-Ethical Reform)

By nine weeks after conception, the fetus responds to light touch on the face, palms of the hand and soles of the feet.6  A light touch on the sole of the foot may cause the fetus to bend his knee and curl his toes.7

The first recorded eye movements come from the 10th week after conception. When something touches the upper eyelid, the eyes roll downward and the muscles around the eye ‘squint’.8  Furthermore, if researchers touch the palm of the fetus’s hand at this age, she curls her fingers in towards the object, but not her thumb. The fetus does not include her thumb in grasping an object until about 13 weeks after conception.9

Dive Deeper
Fingerprints start forming in the 10th week after conception...