Though the average pregnancy is 40 weeks, babies must remain in the womb for at least 39 weeks to fully develop before birth. Those born at 37 weeks or earlier are considered preterm and may experience short- and long-term health issues. Since November is National Prematurity Awareness Month, here are some things to know about pregnancy health and why babies need 39 weeks to grow before birthing. 

Why Do Babies Need 39 Weeks in the Womb?

Organ Development

Babies born prematurely may experience breathing difficulties due to immature lungs that do not allow them to get enough oxygen, requiring constant monitoring with a cardio respirator. An underdeveloped brain at birth can result in delayed physical development, learning, communication, and behavior. Thirty-nine weeks gives enough time for the cells to form so that these vital organs can function independently.

Healthy Weight

Premature babies typically have a low birth weight of five pounds, eight ounces, or less. Since they do not have enough fat to insulate their bodies, they may get cold at room temperature and require placement in an incubator with radiant warmers. Babies in the womb for a minimum of 39 weeks will have enough body fat to prevent them from becoming excessively cold or hypothermic after birth. 

Fewer Vision Problems

Retinopathy can occur due to premature exposure to oxygen, causing blood vessels in the retina to grow rapidly. Babies born very preterm (32 weeks or earlier) are the most at risk of developing vision problems due to scar tissue formation and bleeding. When the baby remains in the womb for 39 weeks, the placenta regulates oxygen levels to prevent vision problems. 

Proper Nutritive Function 

Preterm babies often struggle with nutritive functions, such as sucking and swallowing mechanisms, which can prevent them from being able to eat and drink on their own. They need at least 36 weeks for these reflexes to develop so they can bottle or breastfeed safely.

As soon as you know you’re expecting a baby, allow the compassionate professionals at The Center for Women to guide you through every step of your pregnancy. They provide obstetrics and pregnancy health services to women throughout Mountain Home, AR. Call (870) 425-7300 to book your first prenatal visit. Visit the website to browse through educational materials about pregnancy health and learn more about childbirth classes.