Prenatal Care: Associations with Birth Outcomes and Medicaid at Varying Population Levels

Research Questions and Study Objectives

This study attempts to identify associations between timing of prenatal care, multiple pregnancy outcomes, and Medicaid within and across various aggregate population levels (New York State County, New York State Region, and national). Questions of interest to this study are the following:

• What associations exist between early initiation of prenatal care and various pregnancy outcomes at the national, New York State Regional, and New York State county levels?
• Are there trends in low birth weight, preterm birth, and infant mortality associations across the various aggregate population levels (national, regional, county)?
• At the New York State county level, do certain minorities experience greater benefits from early initiation of prenatal care?
• What are the associations between percent of births financed by Medicaid, early prenatal care, and birth outcomes at the various aggregate levels? Are there trends in these associations across the various aggregate levels?

There exist no previous studies that aim to identify at what population level prenatal care services and Medicaid financed births begin to show associations with pregnancy outcomes. The majority of studies are also prospective in design or use linked data files. This study is concerned with the associations of current prenatal care utilization on various outcomes at a purely population level. Furthermore, no studies on prenatal care have included the indicators of maternal mortality and early childhood mortality, this study includes these outcome measures. A plethora or services, interventions, procedures, medications, and knowledge exist for pregnant women and the influence of prenatal care on pregnancy outcomes may be overshadowed. Comparing associations with prenatal care at increasingly larger population levels may shed light on the variance of prenatal care utilization, content, and quality across New York State and the nation. Since numerous other social and economic factors influence access or utility of prenatal services, it is often difficult to establish causality from associations. However, this study hopes to encourage further research into the functionality of prenatal care within the social and economic context of pregnant women. Specifically, of interest are what prenatal services are found to be most effective, and to what demographics.

Descriptive Stats

Descriptive stats on the county level (n=58, Table 1) variables show that the distributions do not follow a normal distribution. This is expected as the counties across the state are varied in terms of their economies, social structures, demographics, and health care. In the 58 county samples, the mean utilization of early prenatal care was 75.3%, while the mean value for late or no prenatal care was 4.2%. The mean low birth weight, preterm, and infant mortality for all 58 counties was found to be 7.3%, 11%, and 5.6 per 1,000 live births respectively. Descriptive statistics also show that on average for the 58 counties, 37.4% of all births are financed by Medicaid, and 55.9% are financed by private insurance.

Using the county level data set with race (n=16, Table 2), descriptive statistics show that nearly 81% of all white pregnant women received early prenatal care, compared to 61% and 64% of African American and Hispanic mothers respectively. In a similar trend, 71% of white women, 52% of African American women, and 56% of Hispanic women received adequate prenatal care.

The Black infant death rate (16.9 per 1,000 live births) is slightly four times greater than the White infant death rate, and twice the Hispanic infant death rate. Although not as dramatic, the data also indicate that black infants have higher incidence of low birth weight and preterm births, while whites have the lowest. When moving to the smaller county sample of 16, the mean percent Medicaid birth value decreases by 5% to 32%, and percent private insurance births increases by 5% to 60%.

At the regional level (n=8, Table 3), the distribution of the variables still cannot be considered normal. The mean utilization of early prenatal care was found to be 74.7%, while the utilization for low or none was 4.6%. Low birth weight, preterm birth, and infant mortality rates for the 8 regions was 7.8, 11.5, and 6.3 per 1,000 live births respectively.

Surprisingly the total mean infant mortality rate in the smaller sample of counties increases slightly from 5.6% to 6.1%, influenced by proportional increases in the low birth weight and preterm data. It is interesting to note that although Hispanic women utilize early prenatal care at similar rates to that of black women, their birth outcomes are more similar to white women who utilize early prenatal care mucmore.

Using the national level data (n=28, Table 4) the results show that the incidence of low birth weight (11.7) is greater than the New York county and regional samples, while the incidence of preterm (7.8) is lower. The infant mortality rate at the national level is slightly greater, at 6.8 per 1,000 live births, compared to New York county and regional sample values. Nationally, it was found that 36.5% of all births were financed by Medicaid, with the mean per capita spending being $7,237.18. The distribution of all variable is found to be not normal, except for low body weigh which was found to be approximately normal.

Bivariate Correlations

early prenatal care compared to late or none. Although insignificant, a weak association begins to be seen between infant mortality and timing of prenatal care that was expected: Early PNC is negatively associated and late or no PNC is positively associated. No associations are seen at the county level between timing of prenatal care and low birth weight or preterm births.

Bivariate correlation analysis was run on pregnancy outcomes to determine if an association exists between them and timing of prenatal care. At the county level (n=58, Tables 5 & 6) no trends are significant, but surprisingly maternal mortality is slightly associated with

Table 9a: % Early Prenatal Care and % low birth weight by race.

Table 9b: % Early Prenatal Care and % preterm by race.

Table 9c: % Early Prenatal Care and Infant Death Rate per 1,000 live births by race. Table 9a-9c: New York State County level bivariate correlations with race (n=16): associations between timing of prenatal care and pregnancy outcomes by race and county totals.

Comparing the results for adequate prenatal care and early prenatal care it appears that pregnancy outcome associations do not markedly differ within any racial category. However, the greatest benefits are seen in reducing low birth weight among Hispanic infants when compared to associations with early prenatal care.

with the greatest correlation of 0.845 for Black mothers. Early prenatal care is found to have a moderately negative association with Medicaid births when looking within racial categories and a strong negative association exists for the total of all races. Adequate prenatal care is less negatively associated with Medicaid births for all races compared to early prenatal care. Early prenatal care and adequate prenatal care are both found to have weak positive associations with births financed by private insurance.

County level data with race (n-16, Table 11) show that there are positive strong correlations between early prenatal care and adequate prenatal care for all races,

Table 12a: New York State Regional level (n=8) associations between timing of PNC and mortality.

Table 12b: associations between timing of PNC with low birth weight and preterm births.

At the national level (n=28, Table 13) of analysis, early prenatal care has significant negative associations with low birth weight, preterm births, and infant death rate. Similarly, late or no prenatal care was significantly positively associated with low birth weight, preterm birth, and infant death rate. Also, a negative association was found between early prenatal care and Medicaid births, and a weak positive association found between late or no prenatal care and Medicaid births.

At the national level (n=28, Table 14), Medicaid is found to have moderately positive associations with low birth weight, preterm births, and infant death rate.

Table 15: associations between per capita Medicaid spending, timing of prenatal care, low birth weight, preterm births, infant death rate, and % Medicaid births. Table 16 summaries of the most relevant findings & associations:

• Early prenatal care was found to be associated with reduced low birth weight and preterm birth at the national (n=28) and regional levels (n=8); the association diminished at the county level (n=58).
• Early prenatal care was found to be associated with reduced infant mortality only at the national level (n=28), the opposite trend is found at the regional level (n=8), and no trends are observed at the county level (n=58).
• Findings from the county level with race (n=16 Table

17) shows that early prenatal care is associated with reduced low birth weight only for blacks, and reduced infant mortality for white and blacks.

• All other associations indicate an adverse relationship with early prenatal care
• Black infants are found to have the most adverse pregnancy outcomes, and lowest utilization of early prenatal and adequate care.
• Although Hispanics women have almost identical utilization of early prenatal as blacks, their pregnancy outcomes are more similar to white women.

• Adequate prenatal care was not found to be associated with more beneficial pregnancy outcome compared to the respective associations with early prenatal care.
• Adequate prenatal care was found to have the greatest benefits in reducing low birth weight among Hispanic infants.
• Adequate prenatal care was found to reverse the beneficial association seen between early prenatal care and black infant mortality.
• Associations with low birth weight, preterm birth, and infant mortality are found to be rather scattered and independent of birth insurance status at the county level (n=58).
• Early prenatal care was found to be positively associated with % Medicaid births
• % Medicaid births is found to be positively (adversely) associated with low birth weight, preterm birth, and infant mortality (Tables 18-21).
• Per capita Medicaid spending is found to have a positive association with early prenatal care.
• Per capita Medicaid spending is found to have a negative (beneficial) association with low birth weight, preterm birth, and infant mortality.
• Per capita Medicaid spending is found to have an inverse association with % Medicaid births.

Prenatal care has been held as an essential component to reducing pregnancy complications, specifically low birth weight. The net effect of which is to ultimately reduce infant mortality rates in the United States. This study found increased utilization of early prenatal care was associated with low birth weight, preterm birth, and infant mortality at the national level. However, observing these same associations at the regional level show that early prenatal care is associated with infant mortality, although it is negatively associated with low birth weight and preterm births. These associations were nearly nonexistent at the county level of analysis.

It appears that the benefit of prenatal care is seen only at larger aggregate levels of population. This may be due to the inclusion of a threshold proportion of high risk women who have the most to gain from early prenatal care services. Our data indicate that these trends become weaker as the aggregate level of population becomes smaller. Since the national level of analysis included data from various states with various demographics, it represents meta-level associations with early prenatal care which includes a much richer sampling than the New York State Regional and County levels. Within New York State, a single county, or region, may be underrepresented in high risk women, or over represented in low risk women, which may artificially reduce the true benefits of prenatal care. For example, the New York State county data with race show that 61.3% of black women utilize early prenatal care, assuming that the remaining 38.7% of black women are also the majority of black women at risk for adverse pregnancy outcomes (greatest potential to benefit from EPNC), then it is unlikely that the benefits of prenatal care will be seen in this sampling.

Likewise, an overrepresentation of high risk women may also hide the true benefit of prenatal care because early or adequate prenatal care may not prevent or reduce adverse pregnancy outcomes in these women. Even the inclusion or exclusion of a small fraction of It was expected that adequate prenatal care [12] would have more beneficial associations with reduced low birth weight, preterm birth, and infant mortality. However, the results indicated that adequate prenatal care was not associated with reduced adverse birth outcomes any more than early prenatal care was. Again, this may be in part due to high risk mothers requiring enhanced prenatal services, which most often are defined as at least adequate. This is seen when comparing black infant mortality associations with early and adequate prenatal care. The association with early prenatal care was beneficial, while no association was found with adequate prenatal care possibly due to extremely high risk black women requiring adequate PNC more so than lower risk black women. Given the discrepancy between infant mortality between blacks and other races, the beneficial association between early prenatal care and black infant mortality supports the nature of prenatal care as a targeted program for women who are most at risk for adverse pregnancy outcomes [13].

Although early or adequate prenatal care was not seen to benefit birth outcomes for Hispanic infants, the descriptive data indicate better birth outcomes for Hispanics compared to blacks. This indicates that factors outside of the initiation of early prenatal care (excluding health care quality and access) play a role in pregnancy outcomes within minority groups that face similar structural, social, and financial hardships [14].

At the county level (n=58) early prenatal care was found to have an inverse association with percent Medicaid births indicating an issue with the knowledge or availability of prenatal services, or the choice of seeking timely prenatal care. As expected, poverty was found to be positively associated with percent Medicaid births, which supports the findings that poverty is inversely associated with early prenatal care. At the county level (n=58), birth insurance, Medicaid or private, did not influence birth outcomes in any particular direction. However, at the national level (n=28) percent Medicaid births was found to have an inverse relationship with early prenatal care, and adverse associations with low birth weight, preterm births, and low birth weight. Although it may be possible that Medicaid financed births have a lower quality of prenatal services, this is not necessarily true. It is well known that a woman’s decision to initiate timely prenatal care are made in a social, cultural, and historical context that. Many behavioral characteristics of Medicaid women may indirectly prevent, or delay their initiation of timely prenatal care [15].

At the national level (n=28), increased per capita Medicaid spending was found to be associated with increased early prenatal care utilization, and decreased low birth weight, preterm birth, and infant mortality. More significant, is the finding that as per capita Medicaid spending increases the percent of births financed by Medicaid decreases. It appears that as more women are covered for their pregnancy by Medicaid, that the dollar amount of benefits becomes diluted among all Medicaid beneficiaries. This may have major implications on the quality or availability of prenatal care due to reduced Medicaid reimbursement rates for health care providers.

Directions for Further Research and Policy Considerations

One of the major limitations in this study was the lack of quality and content measures. The creation of standardized measures of prenatal care content and quality and the inclusion of these measures in prenatal surveillance and statistics will allow for greater understanding and more accurate evaluation of prenatal care. Quality and content measures can also provide information on women’s experiences and perceptions of prenatal care. Recognition of the salient, qualitative aspects, in women of different racial and socioeconomic groups can help include cultural competency in prenatal care delivery, possibly enhancing benefits for high risk women who are often intimidated or alienated by the health system.

More research is needed in the processes of prenatal care to determine what programs, services, and interventions are most beneficial, for specific demographics. The findings of this study show that prenatal care is associated with benefits in larger aggregate population levels. Augmenting prenatal care to a woman’s specific needs may result in beneficial associations at smaller aggregate population levels since more women are receiving the prenatal care they need, instead of the generic set of services received by both low and high risk women from a wide range of cultural, social, and financial backgrounds. A more individualized approach to prenatal care may yield even greater benefits for women who are of high risk since these are also the women who are most contributing to low birth weight and infant mortality at all aggregate population levels. Of equal importance is the need to identify and remove structural barriers for low income, high risk women, by improving their financial stability, mobility (transportation), and access to established providers of care within the immediate community.

Insurance coverage, whether Medicaid or private, does not guarantee access to needed prenatal services, and access does not guarantee quality or utilization. Promotion, advocacy and political support for direct subsidies to offset the burden of cost sharing to local providers and health centers in low income neighborhoods may benefit a high proportion of Medicaid-eligible pregnant women and their newborns. By enhancing the access, quality, and cultural competency of prenatal care centers in these neighborhoods pregnant women will be more inclined to utilize prenatal care in a scheduled manner.

It was found that as more women have their births financed by Medicaid, that the per capita Medicaid spending decreases and rates of adverse birth outcomes increases. In addition, the findings that increased per capita Medicaid spending is associated with increased early prenatal care utilization and reduced adverse birth outcomes have serious implications on the notion that increasing access to prenatal services through Medicaid expansion will lead to better birth outcomes. This is especially relevant now as Medicaid coverage for women and children has been increasing during the current economic recession. The dilemma is a difficult one, since the majority of women who are at most risk of adverse birth outcomes are dependent on Medicaid, and as more women are covered by Medicaid, the per capita spending decreases, and the likelihood of adverse birth outcomes increases.

To make better use of finite resources, the number of visits and content of visits, should be adjusted accordingly for low and high risk women, especially those on Medicaid. Much evidence shows that a reduced frequency of prenatal visits, four at minimum, is effective, safe, and appropriate for low risk pregnant women [16]. Research to date has clearly shown that the content of prenatal care and not the quantity of visits is the key to healthy maternal and infant outcomes [17]. In actual practice, it is well known that many other industrialized countries which have much lower per capita health spending and reduced prenatal visits for low risk women have continued to have lower rates of adverse birth outcomes, including low birth weight and infant mortality compared to the United States [18]. Updated recommendations for reduced frequency prenatal visits that emphasize the quality and content of prenatal care for low risk women may result in cost savings that can be allocated for the higher risk pool of pregnant women.

Much has been learned about prenatal care since the Institute of Medicine’s recommendations in 1985. Prenatal care may very well be an effective means to deliver necessary obstetric services, but much fine tuning and research is required to observe the beneficial effects of prenatal care for not only pregnant women and their infants, but all women of reproductive age. Data show that half of pregnancies in the United States are mistimed or unplanned and policy makers should recognize the value of preconception education, counseling, and care for women of reproductive age that are at risk for adverse birth outcomes. Prenatal care programs must also be transformed into specific risk appropriate interventions to reduce the differences in adverse birth outcomes that continue to widen among racial groups. Previous policy and clinical aims have been to increase access and frequency of visits. Health care reform provides an opportunity to update prenatal care for the future by revisiting the content and frequency with which prenatal care services are provided, and the development of improved measures to assess whether pregnant women are receiving adequate, timely, beneficial, and culturally appropriate maternal care.