Your baby-to-be's favorite position is the familiar C shape with her legs tucked into her chest and her head pulled toward her knees. She might occasionally stretch out of this position in utero and test out her strengthening muscles. And you'll most likely feel it!
At this point, your baby can hear you more clearly because the bones of her inner ear are developed enough to detect vibrations. Some studies suggest that your baby will feed more vigorously if you read to her in utero, so why not try it? It's fun and it's a great way to connect with your baby. But your baby will be busy exploring other sensations too, stroking her face as she gets to know herself. (Like her fingernails, which have grown long enough to cover her fingertips by now.)
Your baby's heartbeat is so powerful now that you may be able to hear it with just a stethoscope. She continues to practice swallowing, gulping down amniotic fluid not for nourishment but because she's opening and closing her mouth to work her jaw muscles and tongue. Since everything you eat crosses through the placenta, your meals season the amniotic fluid she's swallowing. Your baby's taste buds are now developed enough to taste different flavors. In fact, ultrasounds of babies may even show them grimacing after their mothers have eaten garlic or spicy food. These different tastes prepare your baby to prefer your own uniquely flavored breast milk.
Other changes that you won't feel are happening at the celluar level. For the past week, your baby's bones have begun producing fetal red blood cells. Previously, the baby's liver and spleen were responsible for this job, but as the bones mature, they will be able to sustain your baby's red blood cell needs. By week 30, the spleen will stop producing red blood cells, and a few weeks before birth, the liver will stop, too.
The byproduct of red blood cell production is a substance called bilirubin. Your unborn baby's liver is working to help pass bilirubin through the umbilical cord and on to the placenta, where your liver takes care of the excess. At birth, her liver might or might not be ready to take over the job of removing all the bilirubin from her system. Often, a newborn's body needs a few days to make the adjustment to removing all the bilirubin produced by her body's red blood cell production. Another reason bilirubin often builds up in infants is that their bodies produce more red blood cells than adults. A bilirubin buildup leads to jaundice, a condition where your newborn's skin and eyes appear tinted yellow. The condition is often treated with time in the sun, called phototherapy.
Bilirubin: A yellowish pigment that is left over from the production of red blood cells in the body. The liver disposes of bilirubin through bile that passes through the intestines and then is excreted in urine or stools.
Jaundice: A common condition among newborns where the liver does not remove all the bilirubin from the bloodstream, leading to a yellowing of the skin and eyes. In mild cases, jaundice is often treated with phototherapy, or time in direct sunlight. Signs of jaundice do not usually occur for one to two days after birth.
Images courtesy of the American Institute of Ultrasound in Medicine (AIUM.org).