Changing trends in low birth weight rates among non-Hispanic black infants in the United States, 1991-2004.
We examined trends in low birth weight (LBW, <2,500 g) rates among US singleton non-Hispanic black infants between 1991 and 2004. We conducted Joinpoint regression analyses, using birth certificate data, to describe trends in LBW, moderately LBW (MLBW, 1,500-2,499 g), and very LBW (VLBW, <1,500 g) rates. We then conducted cross-sectional and binomial regression analyses to relate these trends to changes in maternal or obstetric factors. Non-Hispanic black LBW rates declined -7.35% between 1991 and 2001 and then increased +4.23% through 2004. The LBW trends were not uniform across birth weight subcategories. Among MLBW births, the 1991-2001 decease was -10.20%; the 2001-2004 increase was +5.61%. VLBW did not follow this pattern, increasing +3.84% between 1991 and 1999 and then remaining relatively stable through 2004. In adjusted models, the 1991-2001 MLBW rate decrease was associated with changes in first-trimester prenatal care, cigarette smoking, education levels, maternal foreign-born status, and pregnancy weight gain. The 2001-2004 MLBW rate increase was independent of changes in observed maternal demographic characteristics, prenatal care, and obstetric variables. Between 1991 and 2001, progress occurred in reducing MLBW rates among non-Hispanic black infants. This progress was not maintained between 2001 and 2004 nor did it occur for VLBW infants between 1991 and 2004. Observed population changes in maternal socio-demographic and health-related factors were associated with the 1991-2001 decrease, suggesting multiple risk factors need to be simultaneously addressed to reduce non-Hispanic black LBW rates.
Ferré
Cynthia
C
National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health, Centers for Disease Control and Prevention (CDC), Atlanta, GA 30341, USA. cferre@cdc.gov
Handler
Arden
A
Hsia
Jason
J
Barfield
Wanda
W
Collins
James W
JW
D000293:Adolescent; D000328:Adult; D001719:Birth Certificates; D044383:Black People / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D005865:Gestational Age; D006630:Hispanic or Latino; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D016015:Logistic Models; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000208:ethnology*; D011295:Prenatal Care; D012044:Regression Analysis; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult; D001741:Black or African American