Skip Navigation U.S. Department of Health and Human Services
Agency for Healthcare Research Quality
Archive print banner

Low Birthweight in Minority and High-Risk Women

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

Final Report of the Low-Birthweight Patient Outcomes Research Team

Key findings of the Final Report of the Low Birthweight Patient Outcomes Research Team (PORT) are summarized in the abstract below. Select to access clinical highlights of the report or its bibliography.

The Final Report (AHCPR Publication No. 98-N005) is available in limited quantities from the Publications Clearinghouse (P.O. Box 8547, Silver Spring, MD 20907, Telephone 800-358-9295). When supplies are exhausted, bound copies and microfiche can be purchased from the National Technical Information Clearinghouse (NTIS), Springfield, VA 22161 (Telephone 703-605-6000 in Virginia or 800-553-6847 toll-free). To order, request NTIS Accession No. PB98-156565.


The multidisciplinary PORT at the University of Alabama at Birmingham and the Albert Einstein College of Medicine focused on the multiple etiologies of both term and preterm low birthweight. Low-birthweight newborns are those born weighing less than 2,500 grams, either because they are premature (less than 37 weeks' gestational age) or growth retarded (birthweight less than the 10th percentile for gestational age). Nearly 70 percent of all infant mortality is associated with low birthweight, as are about one-third of all handicapping conditions. Some minority women, especially African American women, have substantially higher rates of low-birthweight babies than white women.

The central premise of the conceptual model developed by the PORT, sponsored by the Agency for Health Care Policy and Research (AHCPR), is that low birthweight is attributable to a complex interplay among biological, intergenerational, socioeconomic, and behavioral influences. Therefore, successful prevention of low birthweight demands an interdisciplinary, multiple-intervention approach that simultaneously considers the health care delivery system and the social, psychological, and cultural forces that affect the lives of women during their childbearing years.

Significant progress has been made in studying the practices aimed at the prevention of low birthweight and its major sequelae. Since its inception, the PORT has reviewed a large number of obstetrical practices and other health services interventions by using such research methods as integrative literature review, secondary analysis of large representative data sets, secondary analysis of clinical trial data, and decision-analytic and cost-effectiveness modeling.

Key findings from the PORT's review of secondary data sources include:

  • The strong relationship between bacterial vaginosis in pregnancy and preterm delivery, especially in African American women.
  • A reduction in preterm delivery in women with bacterial vaginosis treated with oral metronidazole and erythromycin.
  • The effectiveness of zinc supplementation for improving birthweight in African American women.
  • The relationship of maternal weight to the benefits of zinc and folate supplementation during pregnancy.
  • The lack of effectiveness of bed rest for preventing preterm delivery.
  • The risks versus the benefits of antenatal testing for fetal well-being and the optimal time during pregnancy in which to initiate such testing.
  • The most cost-effective strategies for treating urinary tract infection during pregnancy.
  • The most cost-effective strategies for maternal screening and treatment to prevent neonatal group B streptococcal sepsis.
  • The usefulness of low-dose aspirin therapy to improve pregnancy outcomes.
  • Which maternal risk factors or biochemical markers/tests best predict subsequent preterm birth.
  • The effectiveness of antenatal corticosteroids for improving the outcomes of very preterm newborns.
  • Variation in the use of corticosteroids and determinants of these variations among perinatal centers.
  • Effects of level of neonatal intensive care and patient volume in neonatal intensive care units on neonatal mortality.
  • Estimates of the cost of neonatal intensive care by gestational age and survival.

In addition to these ongoing studies, the PORT implemented two large-scale projects: (1) a national 27-site randomized trial of a dissemination intervention strategy to improve the use of antenatal corticosteroids in preterm delivery, and (2) a randomized trial of the effectiveness of a combined prenatal intervention targeting African American women identified as at risk for delivering low-birthweight babies.

The findings from the PORT's practice investigations and ongoing work in modeling risk factors related to low birthweight continue to inform the professional literature, providing the groundwork for clinical practice recommendations about the effectiveness of screening and treatment strategies. Findings from the PORT's dissemination and prenatal intervention trials will inform the literature regarding effectiveness of strategies to influence physician practice behavior and also provide valuable information about more effective ways to deliver services to pregnant, low-income, African American women at risk for delivering low-birthweight babies, respectively.

Current as of August 1998


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care