As early as 16 days after conception, a baby’s nervous system has started to develop. By eight weeks, arms and legs start to wiggle, and by the end of the first trimester (the first 12 weeks), the baby is able to make quite a few moves, and its sense of touch has begun to develop.
By around week 16, a baby is starting to suck and swallow and has begun some practice breathing. Moms may feel the baby kicking and moving at 18 weeks. By the end of the second trimester (week 24), the baby is blinking its eyes, and he or she startles to loud noises. The baby may even turn its head toward the sound of mom’s voice.
The baby’s brain more than triples in size during the third trimester. The once-smooth surface of the brain becomes increasingly grooved and indented. In fact, the motor control part of the brain (the cerebellum) increases its surface area 30-fold in the last 16 weeks of pregnancy. The cerebral cortex — the largest part of the brain, responsible for thinking, remembering and feeling — develops rapidly and continues to mature.
Because of rapid brain growth and development in the last trimester, every day and every week in the womb is critical. A recent study published in the Journal of Pediatrics notes that carrying a baby as close to full term as possible is better for the baby’s brain development.
Since a baby’s nervous system develops so early and quickly, it is important for the mother to consume 400 micrograms of folate (folic acid or vitamin B) daily as soon as she starts planning to get pregnant or suspects that she may be pregnant.
This nutrient is essential for fetal cell growth, and consuming enough before and during pregnancy reduces the chance of spina bifida by 70 percent. Folate also may reduce the chances of autism spectrum disorder by up to 40 percent.
Expectant moms and those hoping to get pregnant should take a prenatal vitamin (it should have at least 400 micrograms folate) daily and eat plenty of folate-rich foods, such as leafy green vegetables and whole grains.
Learn more about how babies develop as well as tips on how to take care of them at Baptist Health Lexington’s Expecting Great Things maternity event, from 11 a.m. to 1:30 p.m. March 25 at the Keeneland Entertainment Center. The event is free, and no preregistration is necessary.
Dr. Lynda P. Sanders, a neonatologist with Pediatrix Medical Group of Kentucky, practices at Baptist Health Lexington.