The second trimester of pregnancy is a period of rapid growth and development. Amazingly, for all the hard work both mother and baby are going through, the mother feels incredibly energized compared to the first trimester. Here are just some of the remarkable changes taking place beneath the surface.

Your baby is kicking, flexing, and stretching now. Although his or her acrobatics are quite vigorous, a cushion of amniotic fluid surrounds your baby, so you are unlikely to feel the movement until you are at least 16 weeks pregnant.

Baby’s muscles and skeletal system – complete with bone marrow - are beginning for grow fast now. The skin is translucent and thickening slightly, with developing “peach fuzz” hair on the scalp and eyebrows. Tiny eyelashes form on still-closed eyelids.

Gender starts to take shape as Baby’s ovaries (for girls) or prostate (for boys) move into place and start to develop. An unborn baby’s sex is usually apparent during the routine ultrasound done at 20 weeks gestation.

By the end of the second trimester, a baby produces urine through fully functioning kidneys, has begun to store fat under his or her skin, has developed a sense of direction and balance, and has functioning lungs. A baby born at 27 weeks gestation has an 85% chance of survival.