Undocumented immigrants who do not receive prenatal care are nearly four times as likely to have low-birth-weight infants and seven times as likely to have preterm infants as those who obtain care during pregnancy, according to a two-year retrospective study conducted at a California hospital.1 Furthermore, their infants incur higher expenses for neonatal care. Public funding of prenatal care for undocumented women has become a subject of intense public debate in recent years, particularly in California. Policymakers and voters there have supported proposals, which have been stalled by legal challenges, to eliminate public benefits, including prenatal care, for undocumented immigrants. According to the study's cost-benefit analysis, each dollar cut from prenatal care could cost taxpayers up to $3.33 more in neonatal care.
The study's sample was drawn from 3,351 women who delivered at a large university hospital between January 1, 1996, and December 31, 1997. Among these women, 34% had no legal residency status in the United States. The investigators reviewed medical records to obtain information about the women, their pregnancies and the birth outcomes. They excluded women with past conditions that could lead to low birth weight (less than 2,500 g), preterm birth (delivery before the 37th week of gestation) or perinatal costs unrelated to prenatal care. This reduced the sample to 970 women.
The researchers calculated the cost of care for these women and their infants on the basis of Medi-Cal (California's Medicaid program) reimbursement schedules. Maternity costs included the costs of hospital services and obstetrician fees for intrapartum and postpartum care. The cost of neonatal care included fees for intensive care and for pediatricians and neonatologists. The long-term cost of caring for children who were low-birth-weight was estimated on the basis of costs published in a previous study for health care, child care, special education and grade repetition from birth to age 15.
Ten percent of the women had had no prenatal care; 35% had started prenatal care in the first trimester, 42% in the second trimester and 13% in the third trimester. Women who had received prenatal care and those who had not shared many background characteristics: In both groups, the average age was 25, roughly nine in 10 women were from Mexico, one-third had not given birth before and fewer than one in five had a cesarean delivery. Women who delivered preterm and who had not received prenatal care were similar to their counterparts who had received prenatal care with respect to cigarette smoking, use of alcohol or illicit substances and insurance and employment status.
However, birth outcomes and length of infant hospital stay differed significantly between women who had had prenatal care and those who had not. A higher proportion of women who had not received prenatal care than of women who had received prenatal care had low-birth-weight infants (19% compared with 6%). The same was true for preterm births: Thirty-five percent of women who had not had prenatal care delivered preterm infants, compared with 8% of women who had had prenatal care. Newborns whose mothers had received prenatal care had a mean gestational age at birth of 39 weeks and a mean hospital stay of almost three days, compared with a gestational age of 37 weeks and a mean hospital stay of almost five days for newborns whose mothers had not received prenatal care.
To calculate the relative risk of low birth weight and preterm births between the two groups of women, the researchers used logistic regression techniques, controlling for age, parity, marital status and obstetric risk factors. They found that infants whose mothers had not received prenatal care were nearly four times as likely as others to be low-birth-weight (risk ratio, 3.8) and were seven times as likely to be premature (7.4).
The cost of prenatal care for women in the sample was $702 per woman. Total maternity care costs were similar regardless of whether women had had prenatal care, but the cost of neonatal care differed significantly between the two groups. The average cost of the initial hospitalization for an infant whose mother had not received prenatal care was $2,341 more than that for an infant whose mother had received prenatal care ($3,930 vs. $1,589). The difference was largely attributable to the prevalence of low birth weight among infants born to women who had not received care during pregnancy. On average, neonatal care cost $1,003 for a normal-birth-weight baby and $18,627 for a low-birth-weight infant whose mother had not received prenatal care.
On the basis of the $702 cost for prenatal care and the $2,341 excess hospitalization costs for infants whose mothers had not received prenatal care, the investigators calculated that every dollar spent on prenatal care would save $3.33 in neonatal care costs. To estimate what this ratio would mean for public spending statewide, the researchers extrapolated their figures to the 83,000 pregnancies potentially affected annually among undocumented women. According to their results, while eliminating public funding for neonatal care would save the state $58 million in direct prenatal care costs, neonatal care would cost taxpayers up to $194 million; the state and federal government would share the additional cost of $136 million.
Furthermore, as the investigators note, the impact of prenatal care does not cease after the infant's discharge from the initial hospitalization. The long-term costs of caring for a child who was low-birth-weight averaged $3,247 more if the mother had not received prenatal care ($4,839) than if she had ($1,592). For every dollar cut from public funding of prenatal care for undocumented women, the researchers estimated an increase of $4.63 in the costs of long-term care. This would mean a cost to taxpayers of $211 million annually if public funding of prenatal care for undocumented immigrants were eliminated.
The investigators acknowledge several limitations of their study. Because the sample consisted of undocumented immigrants at one university hospital in California, more than 90% of whom claimed Mexican origin, the findings may not be generalizable to the statewide population of undocumented immigrants. Also, the researchers point out the possibility that undocumented women who received no prenatal care had different risks for adverse birth outcomes from women who received care and that these differences, rather than prenatal care alone, explain the differences in birth outcome. Though they controlled for several variables that may have affected birth outcomes, the investigators acknowledge that they may not have accounted for all the differences in underlying risks.
Despite the study's drawbacks, the researchers conclude that denial of prenatal benefits for undocumented immigrants could significantly worsen birth outcomes and substantially increase the cost of neonatal care. For these reasons, they recommend that public funding of prenatal care for undocumented immigrants not be eliminated.--B. Brown
1. Lu MC et al., Elimination of public funding of prenatal care for undocumented immigrants in California: a cost/benefit analysis, American Journal of Obstetrics and Gynecology, 2000, 182(1, pt. 1):233-239.