07.13.11

Bigger Ain’t Always Better

While big infants like the 16-pound boy from Texas may be adorable, they are not always healthy. Yvonne Bohn, Allison Hill, and Alane Park on the risks of big babies for mother and child.

A 16-pound baby was born to a woman in Texas this week, and while many people were admiring JaMichael Brown's double double chins and rolls of fat on his thighs, there is a more important lesson to this story: when it comes to newborn size, bigger does not mean better.

The average size of an infant born in the United States in 2010 was 7 pounds, 6 ounces. But approximately 6.5 percent of newborns are considered macrosomic, weighing more than 8 and a half pounds. Not only does a macrosomic baby pose significant risks for its mother during delivery, but it also may face a lifetime of health consequences.

A mom-to-be carrying a large baby is likely to face a prolonged labor. The chance of a Caesarean because the baby will not fit through the birth canal is doubled for babies weighing more than 8 and a half pounds. If the mother does deliver vaginally, she is at increased risk for severe tearing of the vagina and rectum as well as significant bleeding after the delivery.

Gallery: World’s Biggest Babies

For the large fetus, the risk of getting stuck within the birth canal, called shoulder dystocia, is 7 percent.  In this obstetrical emergency, the head is delivered but the larger body cannot come out easily, often resulting in nerve injury to the arms or brain damage.  After birth, these babies have difficulty breathing and controlling their own blood sugar. Therefore, they may require admission to the neonatal intensive-care unit (NICU) and a longer hospital stay, as is the case with the Texas baby, who according to various reports is now in the NICU being fed through a tube while doctors try to regulate his blood-sugar levels.

But perhaps the most important consequences for an overweight baby are those that come later in life. New research shows that the environment within the uterus influences future health, a concept called gestational programming. When a fetus is growing too rapidly, brain circuits are wired to affect metabolism and appetite. Ultimately, these circuits become permanent, and change the way body weight is regulated in the future. The angelic chubby baby may be programmed to be an overweight adult. In addition, overweight infants are at higher risk for asthma, cancers, diabetes, and allergies.

The angelic chubby baby may be programmed to be an overweight adult.

Some babies are large because they come from a mom and dad who are tall. Others are large because they arrived after their due date. Gender matters too—boys tend to be larger than girls. Clearly, these risk factors for macrosomia cannot be changed. But the three most significant risks for having an overweight baby are factors that a mother can control: obesity prior to getting pregnant, excessive weight gain during pregnancy, and uncontrolled diabetes. 

So while many think of the squeezable cheeks and Michelin Man arms of these overweight infants as adorable, it is important to consider that these children are set up for a lifetime of struggles with their weight as well as numerous other health problems. It is the responsibility of pregnant women to control the things they can by maintaining a healthy weight, watching what they eat, and following their doctor’s advice for monitoring diabetes.

Dr. Allison Hill is a board-certified OB/GYN and a fellow of the American College of OB/GYN. She and her colleagues Dr. Yvonne Bohn and Dr. Alane Park have been in private practice in Los Angeles for 10 years and have delivered more than 10,000 babies. Together they are the “Mommy Docs,” featured on OWN: The Oprah Winfrey Network’s “Deliver Me” television series, and are the authors of “The Mommy Docs’ Ultimate Guide to Pregnancy and Birth.” For more information, visit www.MommyDocs.com.