Back to Annual Meeting

Back to Annual Meeting

APHA Scientific Session and Event Listing

Recorded presentation

Martha S. Wingate, DrPH, Health Care Organization and Policy, University of Alabama at Birmingham School of Public Health, RPHB 330, 1530 3rd Avenue South, Birmingham, AL 35294-0022, (205) 934-6783, mslay@uab.edu, Greg R. Alexander, MPH, ScD, Department of Pediatrics, University of South Florida College of Medicine, 17 Davis Blvd #200, MDC 15, Tampa, FL 33606, Pierre Buekens, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal St, New Orleans, LA 70112, and Anjel Vahratian, PhD, MPH, Department of Obstetrics and Gynecology, University of Michigan, L4000 Women's Hospital, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0276.

Accurate estimates of the length of pregnancy are valuable for both public health and clinical applications. While the interval between the date of last menstrual period (LMP) and the date of delivery has been the traditional measure of gestational age, the clinical estimate (CE) of gestational age has been touted as an alternative. This study compares these measures and investigates by ethnic groups whether they produce different results in the proportion and risks of certain birth outcomes. The National Center for Health Statistics' linked live birth-infant death cohort files for 2000-2002 were used for this study, selecting cases of single live birth to U.S. resident mothers with both LMP and CE gestational age information. Exact agreement between gestational age measures was greatest at term (37-41 weeks gestation), with non-Hispanic Whites having the highest proportion of agreement. Overall and by race, the proportion of agreement between LMP and CE was lowest among postterm births. Overall and for each racial/ethnic group, the LMP measures resulted in higher proportions of very preterm, preterm, postterm and SGA births compared to CE. Use of different measures of gestational age results in different overall and race-specific rates and risks of very preterm, preterm, postterm, and SGA births. These findings are important to those who utilize the vital statistics data because use of one method could overestimate the preterm and postterm rates. On-going efforts to standardize techniques for gestational age measurement will further efforts related to programmatic and policy initiatives.

Learning Objectives:

• 1. To compare and contrast two different methodologies in gestational age calculation used on U.S. vital records
• 2. To describe how different gestational age measurement methodologies can produce different rates and risks of certain birth outcomes

Presenting author's disclosure statement:

Any relevant financial relationships? No

Recorded presentation