Genes in mother, baby raise risk of preterm birth

CHICAGO - Genes in the mother and the fetus play a role in the risk of preterm labor, a leading cause of infant death and disability, U.S. government researchers said on Thursday.

Genes in the mother and the fetus play a role in the risk of preterm labor, a leading cause of infant death and disability, U.S. government researchers said on Thursday.

They said gene variants in the mother and fetus can make them susceptible to an inflammatory response to infections inside the uterus, raising the risk that a baby will be born early -- before 37 weeks of gestation.

A preterm baby has a 120 times greater risk of death than a baby born full term, and survivors are at risk of breathing difficulties, bleeding into the brain, and having a significant neurological handicap such as cerebral palsy.

"Preterm birth costs the United States $26 billion per year. It is one of the most serious and significant challenges to medicine and society and one whose importance is not fully recognized," said Dr. Roberto Romero of the National Institutes of Health, who presented his findings at a meeting of the Society for Material-Fetal Medicine in Chicago.

Romero said the findings support the notion that preterm delivery is an evolutionary mechanism intended to protect baby and mother from infection.

"We have established that one of every three premature babies is born to a mother who has an intra-amniotic infection," an infection in the normally sterile amniotic fluid that surrounds the developing fetus, Romero said.

Because the response to infections is controlled by genes, Romero and colleagues set out to identify which are most likely to play a role in response to infections in the amniotic fluid.