Related Experiment Videos
Trends in low birth weight infants and changes in Baltimore's childbearing population, 1972-77
Insights
Trends in low birth weight (LBW) increased from 1972-1977, particularly for nonwhites, leading to higher neonatal mortality. Changes in maternal demographics had minimal impact, but increased births to unmarried mothers and those with prior pregnancy losses were linked to rising LBW rates.
Area of Science:
- Public Health
- Epidemiology
- Perinatal Research
Background:
- Low birth weight (LBW) is a significant public health concern with implications for infant mortality.
- Understanding trends in LBW rates and their determinants is crucial for effective intervention strategies.
- Baltimore's linked birth and death records offer a valuable dataset for analyzing LBW trends and associated factors.
Purpose of the Study:
- To examine trends in low birth weight (LBW) rates in Baltimore from 1972 to 1977.
- To assess the impact of changes in childbearing population characteristics on LBW trends.
- To investigate the effect of shifts in birth weight distribution on neonatal mortality rates.
Main Methods:
- Utilized linked birth and death records for the Baltimore population between 1972 and 1977.
- Analyzed unstandardized and standardized LBW rates, controlling for maternal age, education, gravidity, prior pregnancy losses, and marital status.
- Investigated the relationship between demographic shifts and changes in LBW rates and neonatal mortality.
Main Results:
- LBW rates significantly increased annually for both white and nonwhite infants between 1972 and 1977.
- Despite some weight-specific rate declines, overall LBW increases contributed to rising neonatal mortality, especially for nonwhites.
- While maternal age, education, and gravidity changes had minor effects, increased births to unmarried women and those with prior pregnancy losses were associated with rising LBW rates.
- Standardization on marital status and prior pregnancy losses reduced the observed LBW rate increase, particularly when applied simultaneously.
- Significant LBW rate increases persisted for nonwhite teenage mothers and those with less than 12 years of education, irrespective of standardization.
Conclusions:
- Changes in maternal demographics alone did not fully explain the rise in LBW rates during the study period.
- Marital status and history of pregnancy loss are critical factors influencing LBW trends.
- Targeted interventions addressing social determinants like marital status and reproductive history may be necessary to curb rising LBW rates.
- Specific subgroups, such as nonwhite teenage mothers and those with lower educational attainment, require focused attention to reduce LBW disparities.
Abstract:
Linked birth and death records provided the population for a study of trends in low birth weight (LBW) rates in Baltimore between 1972 and 1977 and of the effect of changes in the characteristics of the childbearing population on these trends. The impact of shifts in the birth weight distribution on neonatal mortality rates was also investigated. Trends were analyzed for unstandardized LBW rates as well as for rates standardized on the distributions of maternal age, education, gravidity, prior pregnancy losses, and marital status.Between 1972 and 1977, the 1,500 and 2,000 gm rates rose significantly by approximately 1 infant per 1,000 live births per year among whites and 2 infants per 1,000 live births among nonwhites. Despite declines in rates for most weights, the effect of these increases was a rise in neonatal mortality rates for both races, but especially for nonwhites.The population of women delivering in Baltimore in 1977 became slightly older, slightly more educated, and of higher gravidity than in 1972, but these changes had little impact on yearly fluctuations in LBW rates. In contrast, increases in births to unmarried women and to women with at least one prior pregnancy loss were related to rising LBW rates. For both races, standardization on marital status and prior pregnancy losses diminishes the increase in the LBW rate over the study period, especially when standardization is performed simultaneously for both variables. These findings hold within maternal age, education, and gravidity groups. However, the LBW rates for nonwhite teenage mothers and for nonwhite women with 12 years of less education increased significantly over the study period, regardless of standardization.