What about mom? The forgotten beneficiary of the Medicaid expansions.

• Author: Kutinova, Andrea

1. Introduction

   In the late 1980s and early 1990s, the Medicaid eligibility rules changed substantially. The income thresholds increased and individuals in two-parent families started to qualify. By providing health insurance coverage to all low-income pregnant women and their children, the policy makers hoped to achieve their ultimate goal: to improve health outcomes. Have they succeeded? In an attempt to answer this question, several studies have investigated the effects of the expansions on infant health (Currie and Gruber 1996a, 1997; Dubay et al. 2001; Currie and Grogger 2002), and a few studies have focused on the effects on child health (Currie and Gruber 1996b; Kaestner, Joyce, and Racine 2001). So far, the results have been mixed, leading to a general skepticism about the effectiveness of the Medicaid eligibility expansions in improving health.

   We argue, however, that an important potential beneficiary of the expansions--the mother--has been left completely out of the analysis. To our knowledge, no economic study has investigated the effects of the policy changes of the 1980s and 1990s on maternal health. However, pregnant women have always been a key target population of the Medicaid program. Therefore, without estimating the impacts of the expansions on maternal health (in addition to infant health and child health), any evaluation of the effectiveness of the policy is incomplete. In this paper we attempt to close the gap. In particular, using the Natality Detail Files for 1989 1996, we estimate the relationship between Medicaid eligibility and maternal health outcomes for several treatment groups and a control group. Our results indicate that increased Medicaid eligibility may have led to fewer preventable maternal complications among women most likely to have benefited from the expansions.

2. Background

   Is maternal health an issue in a developed country such as the United States? We believe that it is. As Haas, Udvarhelyi, and Epstein (1993) note in their study, "Although only 10 per 100,000 women die from a complication of pregnancy or childbirth, 60% of women receive medical care for some complication of pregnancy, and 30% suffer complications that result in serious morbidity"(p. 61). An interest in the issues surrounding maternity in the United States is finally awakening among applied economists; for instance, Chatterji and Markowitz (2005) estimate the impacts of the length of maternity leave on maternal depression and women's "overall health" (number of outpatient visits) postpartum. The importance of maternal health has also repeatedly been recognized in national health guidelines--most recently in the Healthy People 2010 (1) (Public Health Service 2000). Also, the Medicaid program itself has been designed to help disadvantaged pregnant women and their infants and children.

   It is therefore surprising to find that the direct health effects of policies targeted at disadvantaged women in the United States have largely been overlooked in the economics literature. After 10 years, an observation made by Jennifer Haas and her coauthors (Haas, Udvarhelyi, and Epstein 1993) remains valid: "Although there has been substantial policy interest in interventions to improve the neonatal outcomes of disadvantaged women, little attention has been paid to the health status of pregnant women themselves" (p.61). As previous research indicates, this is an important oversight. Haas, Udvarhelyi, and Epstein (1993) show that women who receive "satisfactory" prenatal care have better health outcomes (as measured by the occurrence of severe pregnancy-related hypertension, placental abruption, or mother's stay in hospital after delivery at least one day longer than her infant's stay) than women who receive "inadequate" prenatal care, and Conway and Kutinova (2006) demonstrate that timely and adequate prenatal care may increase the probability of maintaining a healthy weight after the birth. This indicates that policies designed to improve prenatal care access may indeed benefit the mothers themselves.

   Past Research on Policies' Impacts on Maternal Health

   We are aware of only one recent economic policy--oriented study that focuses on the health status of disadvantaged women in the United States: Kaestner and Tarlov (2003) investigate the effects of the welfare contractions of the 1990s on women's health (overall health status and mental health) and health behaviors (smoking, drinking, and exercise). In particular, the authors hypothesize that the welfare changes were likely to affect the "employment stress," "organizational stress," and "financial stress" faced by low-income women and thus might have indirectly affected the health status of these women. While the Kaestner and Tarlov (2003) study certainly represents an important contribution to the health economics literature, it does not fill the gap identified above. First, the authors focus on the general health of a disadvantaged population rather than studying the particular health complications women may encounter as a result of pregnancy and/or maternity. Second, the study deals with an indirect impact of a general welfare program on health outcomes and behaviors rather than estimating the effects of a policy--such as Medicaid--designed primarily to improve the health status of its target population.

   Bitler and Currie (2005) somewhat close these gaps by including maternal health outcomes (maternal weight gain and nights hospitalized predelivery and at delivery) in their study of the effectiveness of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) with regard to birth outcomes. However, the program they study has more of an indirect impact on maternal health, and the authors' primary focus is on infant health outcomes. Still, their finding that WIC increases maternal weight gain and may reduce maternal hospitalization at delivery (table 3, p. 84) is suggestive in terms of our research here. First, their finding demonstrates that nutritional policies may benefit the mother's health during pregnancy as well as the infant's health; Improved nutrition is certainly one goal of prenatal care. Second, as discussed later, expanding Medicaid eligibility may result in expanded eligibility for WIC through its adjunctive eligibility (Lewis and Ellwood 1999). It is therefore possible that the estimated effects of Medicaid on maternal, infant, and child outcomes may include the indirect effects of increased WIC participation. For this reason, we investigate whether the most obvious direct avenue for Medicaid to have an effect--improved prenatal care--is evident as well.

   To our knowledge, there are only two economic studies of health policies in the United States that include the expectant mother--those of Currie and Gruber (1997, 2001). However, these studies focus on the effects public insurance has on the medical treatments and procedures provided to the mother (i.e., cesarean section delivery, use of a fetal monitor, receipt of ultrasound, and induction/stimulation of labor). They do not estimate any impact on maternal health outcomes. A similar and more recent study--that of Busch and Duchovny (2005)--estimates the effects of post--Personal Responsibility and Work Opportunity and Reconciliation Act (PRWORA) Medicaid expansions to low-income parents on health insurance coverage and health care utilization (cancer screening and forgoing medical care as a result of cost) among adults. However, this study excludes pregnant women and does not consider the effects on health outcomes. Whether Medicaid (or other health care policies) benefits the mother thus remains an open question.

   Measuring Maternal Health

   As a result of the lack of research in the area, there is not a generally recognized measure of maternal health (an analog to birth weight in infant health studies). Facing this problem in our current study, we have decided to focus on the incidence of three complications to maternal health identified in the medical literature as potentially preventable by prenatal care: placental abruption, pregnancy-associated hypertension, and anemia. In addition, because of the infrequency of these events, we have also employed a summary indicator of maternal health capturing the presence of any of the three complications mentioned above. All of our measures of maternal health can be derived using the information available in vital statistics.

   Placental abruption (2) and pregnancy-associated hypertension (3) are identified in Haas, Udvarhelyi, and Epstein (1993) as important causes of maternal morbidity that can be prevented by interventions during the prenatal period. With regard to placental abruption, Haas, Udvarhelyi, and Epstein (1993) write "Since placental abruption may be associated with poorly controlled hypertension and maternal smoking, this condition may ... be preventable with prenatal intervention" (p. 62). With respect to hypertension, Healthy People 2010 stresses the need for timely and high-quality prenatal care that would "improve maternal health by identifying women who are at particularly high risk and taking steps to mitigate risks, such as the risk of high blood pressure ..." (Public Health Service 2000, p. 16-8). In the public health literature, the role of comprehensive prenatal care in preventing and managing hypertension has long been recognized (Sachs et al. 1988; Scholl, Hediger, and Belsky 1994; Lopez-Jarmillo, Garcia, and Lopez 2005). According to Lopez-Jarmillo, Garcia, and Lopez (2005), prenatal care providers can prevent pregnancy-related hypertension by administering calcium supplements and treating vaginal and urinary infections in women at high risk.

   As for anemia, (4) several recent medical papers have investigated the options for preventing the occurrence of this complication in pregnant women and have concluded that adequate iron therapy during the prenatal period can be very effective (Bashiri et al...