Pregnancy at 13 Weeks
Your baby is about the size of a peach, which is incredible when you think that he was only the size of a baked bean 6 weeks ago. He will grow rapidly over the next few months and, if you feel your lower abdomen, you may just be able to feel the curve of your expanding uterus. External genitalia is now just about developed enough for an ultrasound to detect gender.
Development in 13th Week Pregnancy
Although your baby's organs are formed they still need to mature over the following weeks. His hands and feet are fully developed and making lots of movements as messages pass from the spinal cord to the muscles. His joints and bones continue to get harder (ossify), a process that will continue even after he is born.
Appearance in 13th Week Pregnancy
Your baby's head is still relatively large but his neck is more defined. His arms and legs are growing longer, which makes them more in proportion with the rest of his body. He is sprouting fine hair (lanugo) over his body and at last, although tiny, he looks like a baby.
Movement in 13th Week Pregnancy
Because your baby's neck is now developed he can move his head freely. If you see your baby on ultrasound scan at this stage you would be amazed at how active he is. Because he can make movements with his mouth he seems to be making facial expressions!