"Prenatal development" refers to the process of growth and changes that occur while a baby is still inside its mother's womb before birth. Full definition
The vast majority of brain cells, or neurons, are formed during prenatal development, starting a few weeks after conception. (mindbodygreen.com)
It is at this point in prenatal development that the neural tube develops into the brain and spinal cord and neurons continue to form. (verywellmind.com)
It's possible to get enough Vitamin D, E and K from diet alone to help with prenatal development so prenatal pills for these vitamins isn't necessary. (pregnancy-info.net)