Birth outcomes for pregnant women in residential substance abuse treatment

Evaluation and Program Planning 27 (2004) 199–204 www.elsevier.com/locate/evalprogplan

Birth outcomes for pregnant women in residential substance abuse treatment Kenneth Burgdorfa, Kathleen Dowella, Xiaowu Chena, Tracy Robertsa, James M. Herrellb,* b

a Caliber Associates, 10530 Rosehaven Street, Suite 400, Fairfax, VA, USA Center for Substance Abuse Treatment, Substance Abuse and Mental Health Services Administration, 5600 Fishers Lane, Rockwall II, 8-179, Rockville, MD 20857, USA

Abstract This exploratory study investigates impacts of residential substance abuse treatment in reducing risks of adverse pregnancy outcomes. Pregnancy outcomes for 739 women who delivered in treatment were compared to findings from previous research on outcomes for drugusing women, outcomes for clients’ previous pregnancies, and national infant morbidity and mortality rates. Infants born during their mothers’ treatment had substantially lower rates of mortality and morbidity than all comparison groups, including the general US population. The findings suggest that residential substance abuse treatment can substantially reduce risks of negative birth outcomes for pregnant women. q 2004 Elsevier Ltd. All rights reserved. Keywords: Substance abuse treatment; Pregnant women; Infant mortality; Infant morbidity; Retention

1. Introduction A linkage between cocaine use during pregnancy and elevated rates of adverse birth outcomes such as low birth weight (LBW), premature delivery, and related complications has been well established. A search of the literature published between 1991 and 2001 identified 22 studies showing LBW and/or prematurity rates among women who tested positive for cocaine at delivery (Table 1). Reported LBW rates from the various hospitals represented in these studies ranged from 15 to 45% of live births; the aggregate rate across studies was 34%. All of these figures are well above the national LBW rate for 1997: 7.5% (National Center for Health Statistics, 1999). All reported rates of premature delivery among cocaine-positive women (15 – 43%; 27% overall) are also well above the national rate in 1997: 11.4%. All of these figures are based on standard vital statistics definitions of LBW (5.5£ or less) and premature delivery (under 37 weeks of gestation). Although less extensively studied than cocaine, other substances such as amphetamines, marijuana, opiates, and alcohol have also been linked to increased risk of LBW and/or premature delivery (Datta-Bhutada, Johnson, & Rosen, 1998; Day et al., 1991; Joyce, Racine, McCalla, & Wehbeh, 1995; Little et al., 1990; Ostrea, * Corresponding author. Tel.: þ 1-301-443-2376; fax: þ1-301-594-6762. E-mail address: [email protected] (J.M. Herrell). 0149-7189/$ - see front matter q 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.evalprogplan.2004.01.009

Ostrea, & Simpson, 1997; Sherwood, Keating, Greenough, & Peters, 1999; Stichler, Weiss, & Wight, 1998; Virji, 1991). A clear statistical relationship between prenatal substance abuse and infant mortality has yet to be established, although it has been suggested that there is an increased risk for infant mortality among drug-exposed infants (Ostrea et al., 1997), and several studies have reported unusually high rates of Sudden Infant Death Syndrome among drugexposed infants (Bauchner et al., 1988; Chasnoff, Burns, & Burns, 1987; Durand, Espinoza, & Nickerson, 1990; Fares, McCulloch, & Raju, 1997; Phibbs, Bateman, & Schwartz, 1991). Another concern is that the cost of caring for drugexposed infants is high. In one study, cocaine-exposed infants were found 50% more likely than unexposed infants to require treatment in a neonatal intensive care unit (NICU), resulting in a substantial increase in hospital costs (Joyce et al., 1995). Other researchers have also reported comparatively high hospital costs for drug-exposed infants (Jansson et al., 1996; Stichler et al., 1998) and increased rates of NICU admissions among drug-exposed infants (Berenson, Wilkinson, & Lopez, 1996; Phibbs et al., 1991; Tabor, Smith-Wallace, & Yonekura, 1990). Lifetime treatment costs for a moderately LBW child have recently been estimated to average over $400,000; those for a severely LBW child average twice that amount (US Environmental Protection Agency, 2002).

200

K. Burgdorf et al. / Evaluation and Program Planning 27 (2004) 199–204

Table 1 Recent studies of rates of adverse pregnancy outcomes for women who test positive for cocaine at delivery Low birth weight deliveries n Cocaine-positive Kistin, Handler, Davis, & Ferre, 1996 Kelley, Walsh, & Thompson, 1991 Chazotte, Forman, & Gandhi, 1991 Little, Snell, Trimmer, et al., 1999 Singer, Arendt, Song, Warshawsky, & Kliegman, 1994 Bateman, Ng, Hansen, & Heagarty, 1993 Cohen, Green, & Crombleholme, 1991 Eyler, Behnke, & Conlon, 1994 Handler, Kistin, Davis, & Ferre, 1991 Racine, Joyce, & Anderson, 1993 Kliegman, Madura, Kiwi, Eisenberg, & Yamashita, 1994 Spence, Williams, DiGregorio, Kirby-McDonnell, & Polansky, 1991 Joyce et al., 1995 Sprauve, Lindsay, Herbert, & Graves, 1997 Chasnoff, Griffith, & Freier, 1992 Phibbs et al., 1991 Datta-Bhutada et al., 1998 Datta-Bhutada, Johnson, Rosen, 1998 McCalla, Minkoff, Feldman, et al., 1991 Feldman et al., 1992 Ostrea et al., 1997 Calhoun and Watson, 1991 Total

Premature deliveries

n LBW

%LBW

64 30 42 108 100 361 83 168 408 7934 30

18 10 19 25 33 111 32 47 113 2856 5

29 33 45 23 33 31 38 28 28 36 15

85 483

26 151

31 31

355

111

31

202 128 77 903

89 52 34 185

44 41 44 21

11,561

3916

34

On the positive side, there is evidence suggesting that prenatal care can significantly reduce the likelihood of LBW and premature delivery among pregnant substance abusers (Broekhuizen, Utrie, & Van Mullem, 1992; Datta-Bhutada et al., 1998; Feldman, Minkoff, McCalla, & Salwen, 1992; MacGregor, Keith, Bachicha, & Chasnoff, 1989). One recent study also reported findings suggesting that women in residential substance abuse treatment who remained until delivery had proportionally fewer LBW deliveries than clients who left treatment before delivery (Fiocchi & Kingree, 2001). Occasional reports notwithstanding, however, little documentation is yet available as to whether, to what extent, or under what circumstances substance abuse treatment may impact risks of infant mortality and morbidity among substance abusing women. One problem is that residential treatment programs typically serve small numbers of pregnant women at any given time, making it difficult for provider-based researchers to accumulate enough cases to develop stable statistics on this subject. The distinctive feature of the present report is that it provides pregnancy outcome information for an unusually large number of women who delivered while in residential substance abuse treatment, using data accumulated over a period of years from many small treatment facilities. The data were obtained from 50 demonstration programs funded by the Center for Substance Abuse Treatment (CSAT), in the Substance Abuse and Mental Health Services

n Cocaine-positive

n Premie

%Premie

64 30

19 8

30 25

100 361 83 168 408

40 115 35 73 120

40 32 42 43 29

30 63 85 483 106 355 386 202

6 20 13 136 28 68 85 71

19 32 15 28 26 19 22 35

77 903 91

17 191 34

23 21 37

3995

1078

27

Administration, under its Pregnant and Postpartum Women (PPW) and Residential Women and Children (RWC) Programs (Clark, 2001). Initiated in 1994, these programs funded 50 projects to deliver long-term (6 –12 months) residential treatment to pregnant and parenting women with substance abuse problems. Projects funded in the RWC/ PPW programs had diverse clients, treatment models, and settings, but they were similar to one another in several important ways. All were required to provide: † Gender-specific and culturally appropriate treatment services; † On-site residential care for clients’ infants or young children, to enable clients to maintain supervised parenting relationships throughout their treatment; † Comprehensive services for both clients and their infants/children—substance abuse treatment, prenatal, pediatric, medical, mental health, vocational, parenting, legal, nursery/preschool, transportation, etc. All projects contributed standardized data to a longitudinal cross-site evaluation of the RWC/PPW program, including pregnancy outcome data, where applicable. These data provide the foundation for the present report. The central question examined is whether infant mortality and/or morbidity rates among women who delivered in treatment were lower than would have been expected, absent treatment.

K. Burgdorf et al. / Evaluation and Program Planning 27 (2004) 199–204

2. Methods The 50 RWC/PPW projects contributed standard data describing key client and child characteristics at treatment admission, quarterly throughout treatment, and at treatment exit. From November 1996 to April 2001, the cross-site study received admission data for 4012 RWC/PPW clients, 1231 of whom were pregnant. Some ðn ¼ 114Þ were still in treatment, and still pregnant, at the end of the study data collection. Of the remaining 1117 whose pregnancy status at discharge is known, 739 (66%) gave birth while in treatment, and 378 (34%) left treatment while still pregnant. As part of the treatment admission interview, all entering RWC/PPW clients were asked several questions about their pregnancy histories, including information about any liveborn babies who died within the first year of life. Such infant mortality information was obtained with reference to 10,816 live births prior to this treatment episode. For each of the 739 live births that occurred to women while in treatment at RWC/PPW projects, project staff reported whether or not the infant was LBW and whether or not it was premature, presumably based on project medical records. If the infant died during the quarter when it was born, or at any later time during treatment, that was also reported. All reports of infant deaths, and any inconsistencies or disparities in project-reported information about pregnancy or infant status from treatment entry to discharge, were reconciled directly with the project staff who submitted the information. 2.1. Comparisons and statistical analyses The principal question to be addressed is whether clients who delivered in treatment had more favorable pregnancy outcomes than would have been expected if they had not been in treatment and had continued using drugs throughout their pregnancies. We shall use RWC/PPW clients’ pretreatment infant mortality rate, calculated from information reported at treatment entry, as an approximate indicator of the mortality rate that would be expected from the clients who delivered in RWC/PPW treatment, if they had not been in this kind of program. The comparison assumes that clients were using drugs during their earlier pregnancies and were not in long-term residential treatment programs when they gave birth. To the extent that either of these assumptions is incorrect, the pretreatment mortality figure may understate the ‘true’ mortality risk for infants delivered to untreated substance abusers. As approximate indicators of the rates of LBW and premature delivery that would be expected for RWC/PPW clients if they continued using drugs throughout their pregnancies, we shall use the aggregate morbidity rates from previous studies of women who tested cocainepositive at delivery, from Table 1. These are also not ideal comparison figures. However, since cocaine was by far the most common problem substance for RWC/PPW clients

201

(used by 68% in the six months before treatment entry), and since cocaine-related morbidity rates are well established in the literature, the comparison seems reasonable. In addition to comparing client pregnancy outcomes to outcomes for untreated substance abusing women, we shall also contrast client outcomes to those for the general US population, as documented in vital statistics data for 1997 (National Center for Health Statistics, 1999), the modal year for client deliveries. The expectation is that client outcomes will be somewhere between those for the general population and those for late-pregnancy substance abusers, and hopefully closer to the former than to the latter.

3. Results Client demographic and drug history data were collected at admission to treatment. The majority of RWC/PPW clients who gave birth during treatment were between the ages of 21 and 35 (80%). Their average (mean) age was 30. Just over half were African Americans (56%), 27% were white, and 17% were members of other race/ethnicity groups. Most were unemployed at admission (91%); 44% were high school graduates. Their average (mean) age at first drug use was 15. Most clients (86%) had been in substance abuse treatment prior to the current episode. About half reported either crack cocaine (38%) or powder cocaine (11%) as their primary drug of abuse; alcohol and heroin were the next most common primary substances of abuse (both at 7%), and other substances collectively accounted for the remaining 37%. There were no significant differences in demographic or drug use characteristics between the 739 clients who gave birth during RWC/PPW treatment and the entire population of 4012 women who entered RWC/PPW treatment, for whom data on prior pregnancy outcomes were collected. Similarly, there were no significant pregnancy outcome differences between clients whose primary problem was cocaine and those seeking treatment for other substances. Table 2 shows infant mortality and morbidity rates for RWC/PPW clients who delivered in treatment and for the comparison groups. All rates are expressed as percentages, indicating the number of adverse outcomes per 100 live births. Among the clients’ 739 live births, four confirmed cases of infant death were identified. All occurred shortly after birth, while in NICU care; no additional infant deaths were noted later in treatment or in a follow-up study conducted six months following clients’ discharge from treatment. This represents an infant mortality rate for intreatment clients of 0.5 per 100 live births, considerably lower than 1.2% infant mortality rate calculated for RWC/ PPW clients’ 10,816 previous live births. The in-treatment mortality rate is even slightly lower than the general population reference figure (0.7 per 100 live births), although the difference is not statistically significant.

202

K. Burgdorf et al. / Evaluation and Program Planning 27 (2004) 199–204

Table 2 Infant morbidity and mortality rates for RWC/PPW clients who delivered in treatment, as compared to those for substance abusing women and for all US women, by race/ethnicity Outcome

RWC/PPW in-treatment deliveries ðN ¼ 739Þ

Substance abuser comparison

All US women (N ¼ 3,880,894)

Infant death Premature delivery Black White Other Low birth weight Black White Other

0.4% 7.3% 8.0% 8.1% 5.7% 5.8% 7.1% 4.6% 4.8%

1.2%a ðx2 ¼ 3:7; p ¼ 0:05Þ 27.0%b ðx2 ¼ 10:02; p , 0:001Þ – – – 34.0%c ðx2 ¼ 265:1; p , 0:0001Þ – – –

0.7% ðx2 ¼ 0:9; p ¼ 0:34Þ 11.4% ðx2 ¼ 12:3; p , 0:001Þ 17.6% ðx2 ¼ 47:0; p , :0001Þ 9.9% ðx2 ¼ 2:68; p ¼ 0:10Þ 11.5% ðx2 ¼ 24:4; p , :0001Þ 7.5% ðx2 ¼ 3:1; p ¼ 0:08Þ 13.1% ðx2 ¼ 23:4; p , :0001Þ 6.5% ðx2 ¼ 4:4; p , :05Þ 6.4% ðx2 ¼ 3:2; p ¼ 0:07Þ

a b c

Note. Significance tests are for comparisons to in-treatment deliveries. n ¼ 10,816 previous live births of RWC/PPW clients, as reported at treatment admission. n ¼ 4095, based on 18 previous hospital-based studies of pregnancy outcomes for cocaine-using women. n ¼ 11,561, based on 18 previous hospital-based studies of pregnancy outcomes for cocaine-using women.

As noted earlier, morbidity (LBW and premature delivery) rates are considerably higher for untreated substance abusers (cocaine-positive women) than for US women in general. The expectation was that the findings for RWC/PPW clients who delivered in treatment would be somewhere between these two figures. That was not the case. Unexpectedly, the rate of premature delivery among RWC/PPW clients (7.3 per 100 live births) was not only far better than the comparison figure for cocaine-positive women (27.0%), but for the general US population, as well (11.4%). Both of these differences are highly significant, at p , 0:001: The pattern is similar for LBW rates: the rate for in-treatment clients (5.8 per 100 live births) is far lower than for the cocaine-positive comparison (34.0%, p , 0:0001) and is also lower than for the general US population (7.5%), although the latter comparison is not statistically significant. When client and general population morbidity data are broken out by race/ethnicity, an interesting pattern emerges, particularly in comparisons between African Americans and Caucasians, the two largest groups. Within race/ethnicity groups, the differences between clients and the general population are in the same direction in all cases (with clients having lower morbidity rates than their same-race counterparts), but the differences are greater for African Americans than for Caucasians. This is not because African American clients had better pregnancy outcomes than Caucasian clients, but rather because African American women in the general US population have poorer pregnancy outcomes than their Caucasian counterparts. This is particularly clear for premature delivery rates, which were much higher for African Americans than for Caucasians in the general population (17.6 vs. 9.9%) but were essentially the same for African American and Caucasian clients (8.0 and 8.1%, respectively). The finding that rates of adverse pregnancy outcomes were lower for clients who delivered in treatment than for comparison groups of untreated substance abusers provides

a rough basis for estimating the magnitude of the risk reduction achieved in RWC/PPW treatment. Morbidity/mortality rates for the comparison groups were applied to the 739 RWC/PPW deliveries to generate expected numbers of adverse outcomes for this number of births to substance abusing women, which were then compared to the numbers actually observed. The results of this analysis are shown in Table 3. Compared to the expected numbers of adverse outcomes, the numbers that actually occurred among women in treatment were substantially lower, representing an 83% risk reduction for LBW deliveries; 73% risk reduction for premature deliveries; and 56% risk reduction for infant deaths. The above findings are consistent with the premise that residential treatment can have a substantial beneficial impact in reducing risks of adverse pregnancy outcomes for substance abusing women. However, given the naturalistic (not experimental) nature of the study data, other possibilities must also be considered. One is that the study data could conceivably reflect some form of selection bias. For example, perhaps many of the clients with positive birth outcomes were recruited into treatment very late in their pregnancies, when premature delivery was no longer possible and when other birth problems would be unlikely. Data relevant to these speculations are presented in Table 4, Table 3 Estimated numbers of adverse birth outcomes averted by RWC/PPW treatment Adverse outcome

Percent Expected Actual Difference numbera number (no. averted) reduction

Low birth weight delivery 251 Premature delivery 200 Infant death 9

43 54 4

208 146 5

83 73 56

All figures based on 739 in-treatment pregnancies. For infant deaths, expected number based on outcomes of RWC/PPW women’s previous pregnancies; in other categories, expectations based on previous research for women who tested positive for cocaine at delivery. a

K. Burgdorf et al. / Evaluation and Program Planning 27 (2004) 199–204 Table 4 Pregnancy outcomes for RWC/PPW clients by trimester of pregnancy at admission Outcome

Premature delivery Low birth weight a

Trimester at admissiona First

Second

Third

5.9% 5.9%

7.1% 7.6%

10.2% 6.8%

Excludes 182 cases for which trimester was not reported.

which shows rates of adverse pregnancy outcomes by pregnancy trimester at treatment entry. As can be seen, outcomes were not strongly related to pregnancy trimester at treatment entry. If anything, third trimester admissions had the poorest outcomes, a finding inconsistent with the selection bias hypothesis.

4. Discussion The Center for Substance Abuse Treatment’s RWC/PPW Demonstration Programs were established, in part, to investigate whether residential treatment during the latter stages of pregnancy would materially reduce risks of infant morbidity and mortality. The RWC/PPW cross-site study provides a valuable opportunity to examine this question with pregnancy outcome data for unusually large numbers of treatment sites and individual cases. The findings are most encouraging. RWC/PPW clients’ key infant morbidity rates were much lower than those found in previous studies of infant morbidity in cocaineabusing women. This was true both for clients whose primary problem was cocaine and for clients with other substance problems (pregnancy outcomes for those two client groups did not differ significantly, either overall or within race/ethnicity groups). Infant mortality rates for clients’ deliveries were also lower than for RWC/PPW clients’ previous, pretreatment deliveries. Unexpectedly, morbidity and mortality rates for RWC/PPW deliveries were even lower than for the overall US population. These latter differences were most pronounced among African – Americans, who have especially high rates of adverse pregnancy outcomes in the general US population but not in the in-treatment population. Given the high human and economic costs of the lasting physical and mental disabilities often associated with premature and LBW births, pregnancy risk reduction may be one of the most important benefits of the RWC/PPW program. This study did not attempt to isolate specific features of the RWC/PPW projects that contributed to this apparent risk reduction. Candidate possibilities include the thorough prenatal and medical care that clients received during treatment; clients’ late-term abstinence from tobacco, alcohol, and drugs; and factors such as improved nutrition or reduced stress.

203

Several cautionary notes are in order, however. First, the CSAT-funded RWC/PPW demonstration projects were not typical residential treatment programs. Several reviewers have noted that, among other things, the intensive attention these projects paid to clients’ needs for comprehensive medical, prenatal, and obstetrical care is unusual. It remains to be seen whether other residential programs with less comprehensive services can consistently achieve similarly positive results. Another caveat is that, since pregnancy outcome data were collected locally by clinical or research staff at 50 separate treatment sites, the cross-site study team cannot attest to the accuracy of the information provided by any given site. While the consistency of findings across sites lends credibility to the results, it would seem advisable to replicate the outcome data collection under more rigorously controlled circumstances, with particular attention to the procedures and specifications used in determining gestational age and birth weight. Thirdly, it is troubling that approximately one-third of the pregnant clients who entered RWC/PPW projects left before delivery. Such clients and their fetuses may not have received the full health benefits of treatment, and their absence from the outcome database may have distorted the findings in some way. A preliminary analysis suggests that leaving treatment before delivery was largely associated with medically innocuous factors such as the trimester at entry (clients who had longer to wait were less likely to do so) and extent of contact with their other children (clients having other children who were not in treatment with them were especially likely to leave early). Still, it would seem both clinically and methodologically useful to know more about the reasons some pregnant clients leave residential treatment before delivery and about the health consequences of such decisions, for the clients as well as for their fetuses. This is another recommended priority topic for further study.

Acknowledgements We gratefully acknowledge the contributions of the many RWC/PPW project staff and administrators who assembled the data reported here. This study was supported with grants and contracts from the Center for Substance Abuse Treatment (CSAT), Substance Abuse and Mental Health Services Administration (SAMHSA), US Department of Health and Human Services (DHHS). Views and opinions are those of the authors and do not necessarily reflect those of CSAT, SAMHSA or DHHS.

References Bateman, D., Ng, S., Hansen, C., & Heagarty, M. (1993). The effects of intrauternine cocaine exposure in newborns. American Journal of Public Health, 83, 190 –193.

204

K. Burgdorf et al. / Evaluation and Program Planning 27 (2004) 199–204

Bauchner, H., Zuckerman, B., McClain, M., Frank, D., Fried, L. E., & Kayne, H. (1988). Risk of sudden infant death syndrome among infants with in utero exposure to cocaine. Journal of Pediatrics, 113, 831– 834. Berenson, A. B., Wilkinson, G. S., & Lopez, L. A. (1996). Effects of prenatal care on neonates born to drug-using women. Substance Use and Misuse, 31, 1063–1076. Broekhuizen, F. F., Utrie, J., & Van Mullem, C. (1992). Drug use or inadequate prenatal care? Adverse pregnancy outcome in an urban setting. American Journal of Obstetrics and Gynecology, 166, 1747–1756. Calhoun, B., & Watson, P. (1991). The costs of maternal cocaine abuse. I. Perinatal cost. Obstetrics and Gynecology, 78, 731 –734. Chasnoff, I. J., Burns, K. A., & Burns, W. J. (1987). Cocaine use in pregnancy: perinatal morbidity and mortality. Neurotoxicology and Teratology, 9, 291–293. Chasnoff, I. J., Griffith, D. R., Freier, C., & Murray, J. (1992). Cocaine/ polydrug use in pregnancy: two-year follow-up. Pediatrics, 89, 84–289. Chazotte, C., Forman, L., & Gandhi, J. (1991). Heart rate patterns in fetuses exposed to cocaine. Obstetrics and Gynecology, 78, 323–325. Clark, W. (2001). Residential substance abuse treatment for pregnant and postpartum women and their children: treatment and policy implications. Child Welfare, LXXX, 179 –198. Cohen, H., Green, J., & Crombleholme, W. (1991). Peripartum cocaine use: estimating risk of adverse pregnancy outcome. International Journal of Gynecology and Obstetrics, 35, 51–54. Datta-Bhutada, S., Johnson, H. L., & Rosen, T. S. (1998). Intrauterine cocaine and crack exposure: neonatal outcome. Journal of Perinatology, 18, 183–188. Day, N., Sambamoorthi, U., Taylor, P., Richardson, G., Robles, N., Jhon, Y., Scher, M., Stoffer, D., Cornelius, M., & Jasperse, D. (1991). Prenatal marijuana use and neonatal outcome. Neurotoxicology and Teratology, 13, 329–334. Durand, D. J., Espinoza, A. M., & Nickerson, B. G. (1990). Association between prenatal cocaine exposure and sudden infant death syndrome. Journal of Pediatrics, 117, 909–911. Eyler, F., Behnke, M., Conlon, M., Woods, N., & Frentzen, B. (1994). Prenatal cocaine use: a comparison of neonates matched on maternal risk factors. Neurotoxicology and Teratology, 16, 81– 87. Fares, I., McCulloch, K. M., & Raju, T. N. (1997). Intrauterine cocaine exposure and the risk for sudden infant death syndrome: a metaanalysis. Journal of Perinatology, 17, 179–182. Feldman, J. G., Minkoff, H. L., McCalla, S., & Salwen, M. (1992). A cohort study of the impact of perinatal drug use on prematurity in an inner-city population. American Journal of Public Health, 82, 726–728. Fiocchi, F., & Kingree, J. (2001). Treatment retention and birth outcomes of crack users enrolled in a substance abuse treatment program for pregnant women. Journal of Substance Abuse Treatment, 20, 137– 142. Handler, A., Kistin, N., Davis, F., & Ferre, C. (1991). Cocaine use during pregnancy: perinatal outcomes. American Journal of Epidemiology, 133, 818–825. Jansson, L. M., Svikis, D., Lee, J., Paluzzi, P., Rutigliano, P., & Hackerman, F. (1996). Pregnancy and addiction: a comprehensive care model. Journal of Substance Abuse Treatment, 13, 321–329. Joyce, T., Racine, A. T., McCalla, S., & Wehbeh, H. (1995). The impact of prenatal exposure to cocaine on newborn costs and length of stay. Health Services Research, 30, 341– 358.

Kelley, S., Walsh, J., & Thompson, K. (1991). Birth outcomes, health problems, and neglect with prenatal exposure to cocaine. Pediatric Nursing, 17, 130 –136. Kistin, N., Handler, A., Davis, F., & Ferre, C. (1996). Cocaine and cigarettes: a comparison of risks. Pediatric and Perinatal Epidemiology, 10, 269–278. Kliegman, R. M., Madura, D., Kiwi, R., Eisenberg, I., & Yamashita, T. (1994). Relation of maternal cocaine use to the risks of prematurity and LBW. Journal of Pediatrics, 124, 751 –756. Little, B. B., Snell, L. M., Klein, V. R., Gilstrap, L. C., Knoll, K. A., & Breckenridge, J. D. (1990). Maternal and fetal effects of heroin addiction during pregnancy. Journal of Reproductive Medicine, 35, 159 –162. Little, B., Snell, L., Trimmer, K., Ramin, S., Ghali, F., Blakely, C., & Garret, A. (1999). Peripartum cocaine use and adverse pregnancy outcome. American Journal of Human Biology, 11, 598–602. MacGregor, S. N., Keith, L. G., Bachicha, J. A., & Chasnoff, I. J. (1989). Cocaine abuse during pregnancy: correlation between prenatal care and perinatal outcome. Obstetrics and Gynecology, 74, 882–885. McCalla, S., Minkoff, H. L., Feldman, J., Delke, I., Salwin, M., Valencia, G., & Glass, L. (1991). The biologic and social consequences of perinatal cocaine use in an inner-city population: results of an anonymous cross-sectional study. American Journal of Obstetrics and Gynecology, 164, 625–630. National Center for Health Statistics (1999). Births: final data for 1997 (Vol. 47(18)). National vital statistics report, Washington, DC: National Center for Health Statistics. Ostrea, E. M., Ostrea, A. R., & Simpson, P. M. (1997). Mortality within the first 2 years in infants exposed to cocaine, opiate or cannabinoid during gestation. Pediatrics, 100, 79–83. Phibbs, C. S., Bateman, D. A., & Schwartz, R. M. (1991). The neonatal costs of maternal cocaine use. JAMA, 26, 1521–1526. Racine, A. T., Joyce, T., & Anderson, R. (1993). The association between prenatal care and birth weight among women exposed to cocaine in New York City. JAMA, 270, 1581–1586. Sherwood, R. A., Keating, J., Greenough, A., & Peters, T. J. (1999). Substance misuse in early pregnancy and relationship to fetal outcome. European Journal of Pediatrics, 158, 488 –492. Singer, L., Arendt, R., Song, L., Warshawsky, E., & Kliegman, R. (1994). Direct and indirect interactions of cocaine with childbirth outcomes. Archives of Pediatric and Adolescent Medicine, 148, 959–964. Spence, M. R., Williams, R., DiGregorio, G. J., Kirby-McDonnell, A., & Polansky, M. (1991). The relationship between recent cocaine use and pregnancy outcome. Obstetrics and Gynecology, 78, 326–329. Sprauve, M. E., Lindsay, M. K., Herbert, S., & Graves, W. (1997). Adverse perinatal outcome in parturients who use crack cocaine. Obstetrics and Gynecology, 89, 674–678. Stichler, J. F., Weiss, M., & Wight, N. E. (1998). Examining the cost of substance abuse in pregnancy: patient outcomes and resource utilization. Journal of Perinatology, 18, 384–388. Tabor, B. L., Smith-Wallace, T., & Yonekura, M. L. (1990). Perinatal outcome associated with PCP versus cocaine use. American Journal of Drug and Alcohol Abuse, 16, 337–348. United States Environmental Protection Agency (2002). Cost of low birth weight. Cost of illness handbook, Chap. III.2, Accessed January 30, 2003. Virji, S. K. (1991). The relationship between alcohol consumption during pregnancy and infant birth weight. Acta Obstetrics and Gynecology Scandanavia, 70, 303–308.