Baby Development: Your 1-month-old
The first year of your new baby’s life is an amazing time. Within just 12 months, your baby will transform from a newborn who is totally dependent on you to a toddler who is starting to walk, talk, and exhibit the first signs of independence.
During the first month, your newborn is just getting used to this big, strange new world. And you are getting used to taking care of your baby’s many needs. Below are just a few of the changes you can expect to see during your child’s first month.
Baby Month by Month

Your baby's first year will be full of joys and challenges. WebMD pediatrician
Steven Parker, MD, explains what you can expect as your baby grows and
develops.
It's important to remember that infants who were born prematurely won't follow these baby milestones exactly. They will likely hit each milestone according to their due date, rather than on their birthday. Babies who were born a month early will probably take an extra month to catch up to their peers.
Growth
Don’t be alarmed if your baby loses some weight during the first few days of life. Babies are born with extra body fluid and typically lose up to 10% of their birth weight before they stabilize and start gaining. By their two-week birthday, babies should be back up to their birth weight, and during the first month they’ll gain weight quickly -- putting on between a half-ounce and an ounce a day. Your doctor will check your baby’s weight gain against a growth chart during your well-baby visits, to make sure your baby is growing at the right rate.
Motor Skills
A newborn’s nervous system is still maturing, but babies can accomplish a lot in their first month. You’ll notice that your baby was born with several innate reflexes, including sucking. Soon after birth, your baby will be able to (with a little help from you) latch on to a breast or nipple to feed. If you put your finger inside your baby’s palm, you’ll notice that he’ll close his fist around it (and many a proud father has bragged about the strength of his newborn’s grip). Babies who are startled will quickly flare both arms and legs out and then pull them in. This is called the Moro reflex. Even at 1 month old, your baby has the instinct for walking. If you put a newborn's feet on a solid surface while supporting their body, they'll appear to take a few steps.
Although 1-month-olds may be able to turn their head while lying on their stomach, they don’t yet have the neck strength to support their head while upright. Make sure to put a hand under your baby’s head whenever you lift him.
WebMD Medical Reference

