Doctors' groups urge new language for pregnancy duration
CHAMPAIGN — Expectant moms, the old label, "term" pregnancy, is on its way out.
Two physician organizations — the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine — are discouraging the use of the general label "term" pregnancy and endorsing the use of new, more precise labels that make it clear the only time a baby is born "full term" is during a two-week window.
Under the new definitions, a full-term delivery is one when baby arrives between the week before and the week after week 40 in a pregnancy, with the average pregnancy lasting 40 weeks from the first date of the last menstrual period to the estimated date of delivery.
Traditionally, a "term" pregnancy could refer to a much broader, five-week window that took in the three weeks before through the two weeks after a 40-week pregnancy, the doctors' groups said.
But birth outcomes vary in those five weeks, research has shown, with the lowest rate of uncomplicated pregnancies delivered during the period now defined as full term.
Planned deliveries before 39 weeks shouldn't occur unless there are significant health risks to the mother or fetus, according to Dr. Jeffrey Ecker, chairman of the American College of Obstetricians and Gynecologists committee on obstetrics practice.
"Each week of gestation up to 39 weeks is important for a fetus to fully develop before delivery and have a healthy start," he said in a written statement.
The new labels for "term" deliveries, published in the journal Obstetrics & Gynecology, include:
— Early term: Between 37 weeks and 38 weeks, six days.
— Full term: Between 39 weeks and 40 weeks, six days.
— Late term: Between 41 weeks and 41 weeks, six days.
— Postterm: 42 weeks and beyond.
Dr. Jon Weisbaum, Carle's medical director of women's health services, said the new labels follow what have been American College of Obstetricians and Gynecologists guidelines for deliveries for about the last two decades.
And while Carle doesn't schedule early deliveries without valid medical reasons, that isn't the case everywhere, he said.
"It's a legitimate issue," Weisbaum said.
Doctors have known for a long time there is an important distinction between births occurring at 37 weeks and those occurring at 40 weeks, and how risks mount after 40 weeks, he said. Births at all those various intervals are treated differently for the safety of mom and baby, he said.
It's been impossible to see where patterns of births are occurring before 39 weeks when the label "term" pregnancy" is used, he said, but the new labels will allow for standard data collection at hospitals to make each one's birth practices more visible.
"If the data is entered accurately, using this terminology you'll be able to, almost at a glance, determine what are the obstetric practices at this hospital," he said.