266867 Association between early term birth (37-38 weeks) and long-term mortality

Tuesday, October 30, 2012 : 3:35 PM - 3:50 PM

Casey Crump, MD, PhD , Medicine, Stanford University, Stanford, CA
Kristina Sundquist, MD, PhD , Center for Primary Health Care Research, Lund University, Malmö, Sweden
Marilyn A. Winkleby, MPH, PhD , Stanford Prevention Research Center, Stanford University, Stanford, CA
Jan Sundquist, MD, PhD , Center for Primary Health Care Research, Lund University, Malmö, Sweden
Background: Early term birth (gestational age 37-38 weeks) is associated with increased infant mortality relative to later term birth, but longer-term mortality is unknown. We examined the association between early term birth and mortality through young adulthood.

Methods: National cohort study of 679,981 singleton births in Sweden in 1973-1979, followed up for all-cause and cause-specific mortality through 2008 (ages 29-36 years).

Results: There were 10,656 deaths in 21.5 million person-years of follow-up. Among individuals still alive at the beginning of each age range, we found an association between early term birth and increased mortality in the neonatal period (0-27 days: adjusted hazard ratio [aHR] 2.42, 95% CI 2.10-2.79, P<0.001), postneonatal period (28-364 days: aHR 1.83, 95% CI 1.58-2.11, P<0.001), and early childhood (1-5 years: aHR 1.33, 95% CI 1.13-1.55, P=0.001), which disappeared in late childhood/adolescence (6-17 years: aHR 0.98, 95% CI 0.84-1.13, P=0.76), then reappeared in young adulthood (18-36 years: aHR 1.16, 95% CI 1.06-1.26, P=0.001), relative to individuals born at 39-42 weeks. In young adulthood, early term birth was strongly associated with death from congenital anomalies and endocrine disorders, especially diabetes (aHR 2.94, 95% CI 1.56-5.53, P=0.001).

Conclusions: Early term birth was independently associated with increased mortality in infancy, early childhood, and young adulthood. The optimal gestational ages at birth were 39-42 weeks based on long-term survival. These findings suggest that an evidence-based redefinition of term birth may be warranted that is more compatible with long-term health.

Learning Areas:
Chronic disease management and prevention

Learning Objectives:
1) Identify the current WHO definitions of preterm, term, and post-term birth, and describe how these definitions originated. 2) Identify the long-term health outcomes of “early term birth” (gestational age 37-38 weeks) relative to later term birth. 3) Identify the optimal gestational ages at birth based on long-term survival.

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have been a co-investigator on multiple federally funded grants focusing on the epidemiology of preterm birth, other maternal and child health issues, and chronic disease.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.