Why Preterm Birth Is Riskier for Boys

Photo: Veer / The Bump
Photo: Veer / The Bump

The latest research carried out by more than 50 researchers at 25 different institutions found that baby boys are at higher risk for death and disability in preemie birth than baby girls. The studies, carried out in conjunction with World Prematurity Day (it’s Sunday!), noted that the disabilities preterm delivery puts baby boys at risk for includes learning problems, blindness, motor delays (such as cerebral palsy) and deafness.

Published in Pediatric Research, the six medical papers show that boys are 14 percent more likely to be born preterm than baby girls are. Professor Joy Lawn, team leader of the latest research, says, “Baby boys have a higher likelihood of infections, jaundice, birth complications, and congenital conditions but the biggest risk for baby boys is due to preterm birth. For two babies born at the same degree of prematurity, a boy will have a higher risk of death and disability compared to a girl.” Why? “Even in the womb, girls mature more rapidly than boys, which provides an advantage, because the lungs and other organs are more developed,” she adds.

Another cause that put baby boys at risk? More pregnancy-related conditions in mom. Dr. Lawn adds, “One partial explanation for more preterm births among boys is that women pregnant with a boy are more likely to have placental problems, preeclampsia, and high blood pressure, all associated with preterm births.”

But here’s where it gets interesting: After the first month of life, girls are more likely to die of newborn-related conditions than boys, due to the fact that in most societies girls receive less medical and nutritional care.

So, what’s next? “We need research to inform us about what we don’t understand, such as what causes preterm labor, and to find other things to improve the outcome for survivors,” Edward R.B. McCabe, M.D., Chief Medical Officer of the March of Dimes Foundation, says. “But we also need to use what we know already so we can prevent more preterm births.”

Do you think boys are at higher risk than girls for preemie deliveries?

Plus, more from The Bump:

US Preemie Birth Rates Have Dropped — but Is that Enough?

Why Every Week Matters in Late Pregnancy

Is There Anything I Can Do to Lower the Risk of Preterm Labor?