Full Term Pregnancy Now Considered 37 To 39 Weeks
October 24, 2013

Changes Made To ‘Term-inology’ – When Is A Pregnancy Considered Full Term?

Brett Smith for redOrbit.com - Your Universe Online

Babies born between 37 and 42 weeks of a pregnancy have long been considered “full term,” but now the American College of Obstetricians and Gynecologists is endorsing a change in terminology for some children born during that span of time.

According to the college’s newly published report in the journal Obstetrics & Gynecology, “full term” will now apply only to babies delivered after 39 weeks of pregnancy. Children born between 37 and 39 weeks will be considered "early term." Children born between 41 and 42 weeks of pregnancy will be considered "late term."

"We have increasingly recognized that newborn outcomes are not uniform between 37 and 42 weeks," Dr. Jeffrey Ecker, chair of the College's Committee on Obstetric Practice, told Reuters Health. "Language is important in communicating that it's not just one period of time and to recognize that outcomes do differ.”

Researchers have increasingly been finding that babies born before 39 weeks are not as developed as those born later. Those born after 39 weeks have fewer negative outcomes such as breathing, hearing and learning difficulties, according to the report.

The new definitions were created by a 2012 working group to smooth the progress of data reporting, research and the delivery of healthcare. The report authors noted that a change in terminology could prevent doctors and patients from scheduling medically unnecessary C-sections and labor inductions.

"Doctors can now say to patients that elective deliveries should not be undertaken in the ‘early term' period," Ecker said.

For some doctors, the terminology change was somewhat expected.

"It's not surprising," said Dr. Christopher Glantz, a professor of obstetrics and gynecology at the University of Rochester School who was not involved with the new definitions. "I think we've been moving in this direction for a few years now."

"I think this is good to make sure everyone is using terminology that everyone understands," he told Reuters Health.

"They're just saying we need better precision in our definitions," Glantz added. "Otherwise people use ‘term' to mean all sorts of things."

The obstetrician warned that there are some cases where induced labor before 39 weeks is medically necessary for safety reasons. However, the new terminology should not be seen as an excuse for women to ignore their doctors' advice, he added.

"They should have a conversation together," Glantz said.

A 2009 survey, also published in Obstetrics & Gynecology, found evidence that change in terminology might be necessary. The survey asked 650 women who had recently given birth when a pregnancy reached "full term": 24 percent said 34 to 36 weeks, 51 percent said 37-38 weeks and 25 percent said 39 to 40 weeks.

The survey’s results could explain why early elective deliveries continued to rise even after studies showed the practice held risks for babies, including more breathing and feeding problems and a small increased risk of death.

Advocacy groups, such the March of Dimes, have been campaigning for several years to educate women about the risks of early delivery. Some hospitals now have measures in place to prevent elective early deliveries.