Analyzing genes found in a pregnant woman's amniotic fluid may be able to help doctors tell when a premature infant can be delivered safely. The tests may be able to show when the lungs and potentially other organs have development enough for a viable delivery, according to a new study.
Ideally, a pregnancy should last at least 39 weeks. But some babies must be delivered before then because either the baby or the mother has a medical problem. No test currently exists that can reliably measure how developed organs such as the lungs are, the study notes.
In the study, researchers at Cincinnati Children's Hospital isolated and characterized RNA in amniotic fluid at three different times during the pregnancy: 18 to 24 weeks; 34 to 36 weeks and 39 to 40 weeks. They found that the presence of some RNA and genes at certain times during the pregnancy were associated with characteristics of fetal immaturity, such as respiratory distress.
Researchers identified 257 genes that were expressed differently in the fetuses at 34 to 36 weeks compared to full-term fetuses. Through additional analysis, the authors linked genes expressed differently in preterm fetuses to underdeveloped lungs, decreased lean body mass, and immature feeding patterns.
Preterm birth is the leading killer of babies in the United States, and those who survive an early birth often face serious and sometimes lifelong health challenges, such as breathing problems, jaundice, developmental delays, vision loss, and cerebral palsy, according to the March of Dimes, the leading advocacy group for preventing premature births. Even being born a few weeks too early means a higher risk of death and disability. However, some medical conditions make it necessary for babies to be delivered before 39 weeks of pregnancy. Knowing whether a baby's organs are mature enough can help obstetricians make decisions on planning for a preterm birth.
The research was funded in part by the March of Dimes and way published in the journal BMC Medical Genomics.