Back to Annual Meeting Page		American Public Health Association 133rd Annual Meeting & Exposition December 10-14, 2005 Philadelphia, PA

Abstract #102710

Xu Xiong, MD, DrPH¹, Pierre Buekens, MD, PhD¹, Gabriella Pridjian, MD², Michael C. Henson, PhD², Tri Tran, MD, MPH³, and Juan Manuel Acuna, MD⁴. (1) Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2022, New Orleans, LA 70112, 504-988-1379, xxiong@tulane.edu, (2) Obstetrics and Gynecology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, (3) The Louisiana Office of Public Health, 325 Loyola Avenue, Suite 611, New Orleans, LA 70112, (4) CDC Assignee to The Louisiana Office of Public Health, 325 Loyola Avenue, Suite 611, New Orleans, LA 70112

Background: It has been suggested that a preterm delivery may be associated with fetal sex. Male sex, hormonally involved in the control of labor onset, might contribute to a shortened duration of gestation. The objective of our study was to examine relationship between fetal sex and gestational age and birth weight using a population-based dataset. Methods: We used data from Louisiana birth certificates including 65,708 births in 2002. Univariate and multivariate analyses were performed to examine sex ratio (male/female) in association with gestational duration and birth weight controlled for race and parity. Results: The male to female sex ratio was 1.05 (33,681/32,027) in the study population. Male fetuses were 10% more common than female to be born preterm (adjusted sex odds ratio: 1.10, 95% confidence interval: 1.05-1.16). The male/female ratios of gestational weeks of < 32, 33-36, 37-41, and 42- were 1.14, 1.12, 1.04, and 0.99 (P-trend <0.01). By contrast, male fetuses were 16% less common than female to be born low birth weight [0.84 (0.80-0.89)]. The male/female ratios of birth weight categories of < 1,500, 1,500-2,499, 2,500-3,999, and 4,000- were 1.03, 0.88, 1.03, and 1.74 (P <0.01). Conclusions: Despite male excess preterm births, accelerated intrauterine growth may account for fewer male fetuses born to low birth weight. The skewed sex ratio may give some clues to understanding the causes of preterm birth, low birth weight, and perinatal morbidity and mortality.

Learning Objectives:

• recognize that fetal sex may link poor birth outcomes;
• evaluate fetal sex ratio in association with preterm birth and low birth weight;
• discuss that fetal sex may provide clues to understanding of the causes of preterm birth, low birth weight, and perinatal morbidity and mortality

Keywords: Sex, Pregnancy Outcomes

Presenting author's disclosure statement:

I wish to disclose that I have NO financial interests or other relationship with the manufactures of commercial products, suppliers of commercial services or commercial supporters.