chasnoff, prevalence of illicit drug...

N Engl J Med 1990; 322: 1202-1206

April 26, 1990

SECTION: SPECIAL ARTICLE

LENGTH: 3456 words

TITLE: The Prevalence Of Illicit-Drug Or Alcohol Use During Pregnancy And Discrepancies In Mandatory Reporting In Pinellas County, Florida.

SOURCE: From the Northwestern University Medical School, Chicago (I.J.C.); Operation PAR, Inc., St. Petersburg, Fla. (H.J.L.); and the Addictions Research Institute of Illinois, Chicago (M.E.B.). Address reprint requests to Dr. Chasnoff at the National Association for Perinatal Addiction Research and Education, 11 E. Hubbard St., Suite 200, Chicago, IL 60611.

Supported by a grant from the Juvenile Welfare Board of Pinellas County, Florida.

AUTHOR: Chasnoff, Ira J.; Landress, Harvey J.; Barrett, Mark E.

ABSTRACT:

Florida is one of several states that have sought to protect newborns by requiring that mothers known to have used alcohol or illicit drugs during pregnancy be reported to health authorities. To estimate the prevalence of substance abuse by pregnant women, we collected urine samples from all pregnant women who enrolled for prenatal care at any of the five public health clinics in Pinellas County, Florida (n = 380), or at any of 12 private obstetrical offices in the county (n = 335); each center was studied for a one-month period during the first half of 1989. Toxicologic screening for alcohol, opiates, cocaine and its metabolites, and cannabinoids was performed blindly with the use of an enzyme-multiplied immunoassay technique; all positive results were confirmed.

Among the 715 pregnant women we screened, the overall prevalence of a positive result on the toxicologic tests of urine was 14.8 percent; there was little difference in prevalence between the women seen at the public clinics (16.3 percent) and those seen at the private offices (13.1 percent). The frequency of a positive result was also similar among white women (15.4 percent) and black women (14.1 percent). Black women more frequently had evidence of cocaine use (7.5 percent vs. 1.8 percent for white women), whereas white women more frequently had evidence of the use of cannabinoids (14.4 percent vs. 6.0 percent for black women).

During the six-month period in which we collected the urine samples, 133 women in Pinellas County were reported to health authorities after delivery for substance abuse during pregnancy. Despite the similar rates of substance abuse among black and white women in our study, black women were reported at approximately 10 times the rate for white women (P<0.0001), and poor women were more likely than others to be reported.

We conclude that the use of illicit drugs is common among pregnant women regardless of race and socioeconomic status. If legally mandated reporting is to be free of racial or economic bias, it must be based on objective medical criteria. (N Engl J Med 1990; 322:s202-6.)

TEXT:
Previous estimates of the frequency with which illicit drugs and alcohol are used by pregnant women have relied on data collected in hospital-based populations before, at the time of, or after delivery n1 n2 n3. In addition, the majority of hospitals involved in such studies have served urban populations composed largely of minority-group members of relatively low socioeconomic status. We undertook a population-based study of the prevalence of the use of illicit drugs and alcohol by pregnant women who received prenatal care in Pinellas County, Florida, either at public health clinics or in private obstetrical offices.

Pinellas County is an urbanized area with a population of 860,000. Located on a peninsula on the west coast of Florida, it is the most densely populated and most developed county in Florida, with over 3100 persons per square mile. Its major cities are St. Petersburg (population, 243,000) and Clearwater (population, 101,082). Pinellas County is contiguous with Hillsborough County, in which the major city is Tampa. The Tampa-St. Petersburg standard metropolitan statistical area has a population of 2 million people. The population of Pinellas County has increased approximately 18 percent per year since the 1980 census. The minority population has increased by 25 percent over the same 10-year period. Overall, minority groups currently make up 9 percent of county residents. Approximately 27 percent of the residents are 65 years of age or older, 55 percent are between 18 and 64, and 18 percent are 17 or younger n4.

The major public-assistance programs that affect children in Pinellas County are Aid to Families with Dependent Children, the food-stamps program, and Medicaid. During the fourth quarter of 1988, an average of 6256 families per month were receiving Aid to Families with Dependent Children n5. Prenatal health care services are available for indigent women at five public clinics throughout the county. In addition, 49 physicians (46 M.D.s and 3 D.O.s) in the county provide private prenatal care in 20 individual or group practices. The birth rate in the county has remained steady. From January 1, 1989, until June 30, 1989, there were 5178 live births; 793 of these infants were born to black women, 38 to Asian women, 2 to American Indian women, 55 to Hispanic women, and 4290 to other white women (Cushing B, Pinellas County Health Unit, Pinellas County, Fla.: personal communication).

In March 1987, a statewide policy was adopted in Florida that required the reporting of births to mothers who used drugs or alcohol during pregnancy. Hospitals were required to notify local health departments when such cases were suspected. Chapter 415.503(8)(a)2 of the Florida Child Abuse Statutes defines reportable harm" to a child's health or welfare as including physical dependency of a newborn infant upon any . . . controlled drug." The Florida Department of Health and Rehabilitative Services (HRS) has developed regulations governing the reporting of the birth of infants to mothers suspected of drug or alcohol involvement" n6. These regulations specifically require reporting when there is an admission by the mother of drug use during pregnancy, or positive maternal drug screen during pregnancy or the early postpartum period, or a positive newborn drug screen." Documentation of maternal drug abuse or drug addiction is not necessary for an infant to be included under the mandatory-reporting regulations. Thus, the regulations focus on the infant's exposure, not the mother's pattern of drug or alcohol use.

Special procedures have been adopted in Pinellas County to comply with these regulations. On referral of a newborn suspected of having been exposed in utero to an illicit drug or alcohol, community health nurses are required to make a home visit to determine the suitability of the home and whether further intervention is required; such intervention might include continued supervision by a community health nurse, the involvement of the state protective services, with the possibility of removing the child from the mother's custody, or the referral of the mother to specialized drug-treatment and intervention programs.

Methods

A urine sample was collected from every woman who enrolled for prenatal care during a one-month period at each of the five Pinellas County Health Unit clinics and from every woman who entered prenatal care during a one-month period at the offices of each of 12 private obstetrical practices in the county. All the samples were collected between January 1 and June 30, 1989. The 12 private practices that participated in the study provided prenatal and intrapartum care to 70 percent of all the pregnant women who obtained private health care in Pinellas County. The remaining 8 obstetrical practices did not differ from the 12 participating practices in terms of their location, hospital privileges, or university teaching affiliation. The institutional review board of the Pinellas County Health Department approved the protocols and procedures before the study began.

The urine sample was obtained at each woman's first prenatal visit. Because no personal identification was attached to the sample, so that the results could not be traced back to the individual woman, the woman's consent was not required. Each sample was labeled with the woman's age, her race or ethnic group, and the ZIP Code of her residence and was sent to the laboratories of Operation PAR, Inc. Operation PAR is a comprehensive substance-abuse agency with a nonprofit laboratory licensed by the State of Florida and accredited by the College of American Pathologists. The laboratory participates in blinded proficiency-testing programs sponsored by both the College of American Pathologists and the American Association of Bioanalysts and has consistently had a 100 percent proficiency rating.

Samples were assayed by personnel who had no knowledge of the site of origin or the characteristics of the mother. Toxicologic screening was performed with enzyme-multiplied immunoassay techniques; all positive samples were reanalyzed. The manufacturer's recommended cutoff levels were used to determine the presence of a drug or drug metabolites. Samples were tested for alcohol, opiates, cocaine and its metabolites, and cannabinoids (including tetrahydrocannabinol). The results were recorded according to the code number assigned to the mother.

For the same six-month period during which urine samples were collected for toxicologic analysis, we reviewed records from the Pinellas County Health Unit on women reported for drug or alcohol use during pregnancy and recorded the mother's ZIP Code, race or ethnic group, and drug-use pattern. These records included data on women reported to the Health Unit on the basis of alcohol or drug use identified by toxicologic analysis of urine samples obtained at the time of delivery or on the basis of the mother's disclosure of alcohol or drug use.

The mothers' ZIP Codes were used to assign the women to socioeconomic-status categories according to the median annual income of the families in each ZIP Code area. The three income levels used were low (<$ 12,000), middle ($ 12,000 to $ 25,000), and high (>$ 25,000) n7. Demographic data on the mothers and the results of toxicologic testing of urine samples were analyzed by chi-square analysis for nonparametric data and t-tests for parametric data. A z-test was used to assess differences in the proportion of white and black women reported for substance abuse during pregnancy under the state's mandatory-reporting law. All directional P values were for two-tailed tests of significance.

Results

During the one-month study periods for the clinics and private practices, a total of 380 women entered one of the five Pinellas County health clinics for prenatal care, and 335 women entered private obstetrical care in one of the 12 practices we studied. Thus, a total of 715 urine samples were collected at the women's first prenatal visits. No woman's urine sample was lost, and an adequate volume of urine for analysis was available in all cases. There were significant differences in racial distribution and socioeconomic status between the public and private patients (P<0.0001; Table 1). The mean ages of the two groups of women were also significantly different (P<0.001); the mean age (+/- SD) of the women who received care in public health clinics was 22.6 +/- 5.5 years, and that of the women cared for in private offices was 26.6 +/- 5.2 years.

*Table 1. Demographic Characteristics and Drug-Use Patterns of Pregnant Women, According to Type of Health Care Provider *.

**TABLE OMITTED**

Of the 715 women, 14.8 percent had positive results on toxicologic screening of urine for alcohol, cannabinoids, cocaine, or opiates (Table 1). When alcohol was eliminated from the analysis, 13.3 percent of the urine samples were positive for an illicit drug. There was no significant difference in the prevalence of positive results between public and private patients. The prevalence of positive results of screening for the individual drugs was also similar in the two groups, with the exception of cocaine, which was identified more frequently in the urine samples from the women who received care from public clinics. Of the 106 urine samples with positive results on toxicologic analysis, evidence of more than one substance (alcohol or the various drugs) was found in those of 7 women who received care in the public clinics and 5 who received care from private physicians.

Demographic factors and drug-use patterns were evaluated for white and black women. There were too few Asian and Hispanic women in the total sample for us to analyze these groups separately. There was a significant difference between white and black women in the distribution according to socioeconomic status, for which we used the median family income in the woman's ZIP Code area as a measure (Table 2). White women (mean age +/- SD , 25.6 +/- 5.5 years) were significantly older than black women (21.7 +/- 5.4 years; P<0.001). The rate of positive results on toxicologic testing of urine samples was 15 percent among the black and white women combined; the rate for white women (15.4 percent) was slightly higher than that for black women (14.1 percent; Table 2). The results of testing for specific drugs indicated that more black women used cocaine than white women; the opposite was true for cannabinoids.

*Table 2. Socioeconomic Status and Drug-Use Patterns of Black and White Women *.

**TABLE OMITTED**

When socioeconomic status, the type of health care provider, race or ethnic group, and age were entered as independent variables in a multiple regression analysis, with a positive result on screening for any drug as the dependent variable, the four independent variables accounted for only a small amount of the observed variance (R(sup 2) = 0.02). In particular, socioeconomic status and race or ethnic group did not predict a positive result on toxicologic testing.

During the six-month study period (January 1 to June 30, 1989) in which we collected urine samples, 133 women were reported to the health authorities in Pinellas County for drug or alcohol use in pregnancy; 48 were white, and 85 were black. There was no significant difference in socioeconomic status between the black and white women who were reported, although the women were more likely to be of low socioeconomic status than were the women with positive results on toxicologic testing of urine samples in our study. There was a higher rate of cocaine use among the reported black women and a higher rate of marijuana use among the white women (Table 3). This finding was consistent with the results of the urine tests, described above. The proportion of white women reported for any drug use (48 of 4290 who delivered live-born infants) was 1.1 percent, whereas the proportion of black women reported for any drug use (85 of 793) was 10.7 percent. Thus, a black woman was 9.6 times more likely than a white woman to be reported for substance abuse during pregnancy. This difference was evident despite the fact that in the population we surveyed the frequency of positive results on toxicologic testing of urine samples obtained at the first prenatal visit was similar for white women (15.4 percent) and black women (14.1 percent). By means of a test of difference between proportions, we found that the proportion of white and black women reported to public health authorities for the investigation of fetal or neonatal exposure to drugs or alcohol was significantly different (z = 8.67, P<0.0001); the rate of reports was 10 times higher among black women. This racial difference persisted when the reported women were analyzed according to the type of prenatal care they received (public or private). Among the women who received care at public health clinics, although black women made up 44 percent of the patient population, 67 percent of the women reported for substance abuse were black. In the private obstetricians' offices, black women made up less than 10 percent of the patient population but 55 percent of those reported for substance abuse during pregnancy.

*Table 3. Black and White Women Reported after Delivery for Substance Abuse *.

**TABLE OMITTED**

Discussion

A number of studies have now documented the harmful effects of the abuse of both licit and illicit substances on the outcome of pregnancy and delivery n2 n3, n8 n9 n10 n11 n12 n13 n14. Some states (such as Illinois and California) have passed child abuse-reporting laws requiring that any newborn with positive results on toxicologic testing of urine for licit or illicit drugs be reported to the state child-protection services or state health authorities. Minnesota passed a law in 1989 that required the reporting of pregnant women if they had positive results on urine testing. Florida requires that a woman with a history of using illicit drugs or alcohol during pregnancy be reported after delivery, even if her urine and the baby's are negative at delivery. The precise definition of fetal exposure to alcohol and drugs and the implications of reporting vary from state to state, but in some instances infants are taken from their mothers and placed in protective care.

Previous studies have not adequately evaluated the prevalence of the use of illicit drugs or alcohol during pregnancy among women who receive care from private obstetricians. In a study of women receiving prenatal care at Parkland Hospital in Dallas, Little et al n3. found that 10 percent reported cocaine use and 3 percent amphetamine use during pregnancy. Frank et al n2. found that among women enrolled in a comprehensive prenatal-assessment program at Boston City Hospital, 28 percent of urine samples screened by toxicologic testing were positive for marijuana and 17 percent were positive for cocaine or its metabolites. A survey of 36 selected hospitals found that 11 percent of newborns had been exposed to an illicit substance at some time during the pregnancy n1. Although the last study included three hospitals that served private obstetrical patients, all three of these studies relied primarily on hospital-based populations in urban areas with largely poor populations.

In the present study we surveyed women who received care from both public and private providers. The rapid changes in the population of Pinellas County, due in part to immigration, may make it unusual, but two important factors of general relevance emerge from our data. First, the overall prevalence of drug or alcohol use, documented by positive results on toxicologic testing of urine samples obtained at the first prenatal visit, was similar among women who received care from private physicians and those cared for at public health clinics. Second, the rate of substance use by pregnant women, as documented at the first prenatal visit, was similar for whites and blacks.

Toxicologic studies of urine samples are limited, in that a positive result reveals only that a particular substance was used within a specific period of time before testing. Such tests do not indicate the frequency of use or the amount used. The use of alcohol, because of its rapid metabolism and excretion in the urine, is very difficult to document by toxicologic testing of urine samples obtained eight or more hours after consumption; thus, the use of alcohol is almost certainly underreported in our data. We did not attempt to determine the prevalence of substance abuse but only the frequency with which evidence of substance use was observed in pregnant women, as documented by positive results on urine tests. The Florida reporting regulation does not require documentation of maternal addiction or drug abuse but only reasonable cause to suspect" maternal drug or alcohol use, a vague requirement that can lead to variations in reporting.

Such variations in the reporting of women to public health authorities were evident in Pinellas County in the fact that a significantly higher proportion of black women than white women were reported, even though we found that the rates of substance use during pregnancy were similar. It could be postulated that white women were more likely than black women to cease using illicit drugs or alcohol on entering prenatal care and therefore less likely to be reported after delivery. However, several studies n3 n9, n15 n16 n17 have shown that the use of drugs or alcohol during pregnancy rarely ceases unless intensive therapeutic intervention is instituted. The infants born to black women could have had more severe symptoms of drug exposure than the infants born to white women, especially since there was a higher rate of cocaine use among black women than white women. In addition, persons who are acutely intoxicated with cocaine are more readily identified than persons who have used marijuana. This difference may have prompted physicians to test black women and their infants more frequently than their white counterparts. It is also possible that physicians consider cocaine more damaging to the fetus than marijuana, the drug most commonly used by the white women. Nevertheless, several studies have demonstrated adverse effects of marijuana use during pregnancy n11 n12, n18 n19 n20.

There may be a reluctance on the part of private obstetricians and hospitals to assess their patients' drug or alcohol use, either by history or by laboratory tests, for fear of adverse patient reactions and the loss of future referrals. Furthermore, private physicians often share the same social network, either directly or indirectly, as their patients. This fact could lead to a reluctance on the part of these physicians to identify and report substance use in private patients. Since a greater proportion of white women than black women were private obstetrical patients, a relative lack of assessment may explain the lower rate of reporting for white women.

Physicians who care for large numbers of minority patients tend to be located at teaching hospitals. Hospital faculty members may be more aware than private practitioners of current techniques to identify and refer infants with intrauterine drug or alcohol exposure and may therefore be more likely to find evidence of maternal substance use.

Finally, the preconception that substance abuse, especially during pregnancy, is a problem that affects minority groups, urban populations, and lower socioeconomic groups could bias physicians in identifying substance exposure in newborn infants. This would result in more frequent suspicion of intrauterine drug exposure and, thus, a higher rate of testing and reporting of infants born to black or poor women.

The present study cannot fully differentiate among the factors that could produce higher rates of reporting of black or poor women than of white or more affluent women. To clarify the influence of these factors, it will be necessary to undertake population-based studies in which urine samples obtained at delivery are tested and the reporting rates correlated with those results. However, even given its limitations, our study has important implications for states that are now developing child-protection laws covering substance use in pregnancy. It is clear that standards based on medical criteria for the identification of intrauterine drug or alcohol exposure must be an integral part of all state legislation, especially when the reporting of such cases is required by state law.

We are indebted to Jeanne McCarthy, M.D., Ph.D., for her assistance in gaining the participation and cooperation of private obstetricians in Pinellas County.

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