Born too soon pg. 2
Yet there is a problem: This year more than half a million babies in the United States will be born too soon – before 37 weeks of the usual 40 week term. The nation’s preterm rate, 12.8 percent, is among the highest in the Western world. It also has been increasing rapidly, by 10 percent during each of the past four decades, for reasons that are not well understood.
That’s why Muglia and others have been thinking about the evolutionary “push” in human birth. It could point to the genes that control the biology of birth timing – and which might participate in causing birth to occur too early.
Premature babies spend their first days, weeks and even months in a neonatal intensive care unit (NICU). They face an increased risk of death and serious medical complications, including chronic lung disease, cerebral palsy (prematurity is the main cause of cerebral palsy), learning delays and other neurological, digestive, vision and hearing problems.
The cost of these complications is enormous – an estimated $26 billion a year in the United States. But Muglia says that’s an underestimate. “You really can’t put a price on some of the very long term functional deficits these children have,” he says. “The strain on families and society, both emotionally and financially, is tremendous.”
Prematurity also appears to increase a person’s susceptibility to diseases like diabetes, obesity and cardiovascular disease in adulthood.
Some babies are delivered early for medical reasons – our increased ability to monitor fetal well-being enables us to detect and deliver a baby that is in distress. Medical indications account for about 25 percent of all preterm births.
The remaining 75 percent are spontaneous preterm births. About half of these can be linked to a factor known to increase risk for premature birth – such as infection, maternal drug use or multiple gestation. Assisted reproductive technologies, such as in vitro fertilization, and women having children later in life both have contributed to an increase in the number of twin pregnancies.
The other half, representing nearly 40 percent of all preterm births, has no known cause.
Doctors currently are ill-equipped to stop preterm birth. Once labor begins, it can be delayed for perhaps two days – long enough to administer steroids that can help fetal lung maturation, but not long enough to change the frequency of adverse outcomes.
“I think the question of birth timing is one of the most important questions in reproductive biology right now,” Muglia says. “Only by preventing the early life adverse outcome of premature birth can we block acute and later adult problems as well.”
View Related Article: