The Second Trimester

Weeks 14 thru 16 Gestational Age

The fetus’s skin is transparent (see-through) and a fine hair called lanugo begins to form on the head. The fetus can suck and swallow bits of amniotic fluid. Fingerprints which make each human unique have developed on his or her tiny fingers. Flutters may be felt in mom’s growing belly as the fetus begins to move around more. The fetus has reached 6 inches in length and weighs about 4 ounces. Often you can see the genitals on ultrasound.

Weeks 17 thru 20 Gestational Age

Mom probably feels the baby moving by now. He or she even has sleeping and waking patterns and a favorite sleeping position. Reflexes such as blinking and frowning are now developed. Your baby is about 8 inches long and weighs about 12 ounces. The image to the right shows an ultrasound at 18 weeks.

Weeks 21 thru 23 Gestational Age

Your baby looks more like a newborn infant as his or her skin becomes less transparent and fat begins to develop. He or she can feel pain more intensely that at any other time in development. More organs like the liver and pancreas are working hard to develop completely. Your baby is about 10-11 inches in length and weighs about 1 - 1 ¼ pounds.

Weeks 24 thru 26 Gestational Age

If your baby was delivered now, he or she may survive with the assistance of medical technology. The fetus has a startle reflex, and the air sacs in the lungs (for breathing) have begun forming. The brain will be developing rapidly over the next few weeks. And his or her ear has developed enough to recognize mom’s voice, her breathing, and even her heartbeat. The fetus has reached about 14 inches in length and weighs about 2 pounds.