The Impact of Prenatal Cocaine Exposure: Studies of the Developing Infant Susan H. Landry and Julie A. Whitney This article traces several major phases of research evaluating the development of infants exposed to cocaine. Although initial studies focused on the medical and neurobehavioral status of the neonate, these studies often lacked appropriate comparison groups, attention to polydrug use, and follow-up after hospital discharge. As studies began to include longer follow-up periods and the types of comparison groups necessary to evaluate the unique effects of cocaine versus factors such as poverty and polydrug use, the deleterious effects of cocaine exposure were not as apparent. Although most early studies focused only on mental and motor outcomes, recent studies evaluating learning pro- cesses, emotional development, and the effects of cocaine-exposed infants' unique caretaking envi- ronments may provide more detailed descriptions of the outcomes of this growing population. This article discusses numerous methodological issues that continue to challenge this complex research area and recent research efforts that may prove beneficial in guiding future studies. Copyright 9 1996 by W.B. Saunders Company Cocaine: Its Reappearance p renatal influences and insults on child de- velopment have been a critical area of scien- tific study for many years. The popularity of many illicit drugs has waxed and waned through- out history, with cocaine the most recent to re- surface and regain epidemic proportions. Prena- tally cocaine-exposed infants and their mothers are a subgroup of our society that has demanded great attention within the past 10 to 15 years. These infants are at higher risk for medical and developmental problems than infants of non- drug-abusing mothers. This article highlights the historical and cur- rent research developments and concludes with the future investigative directions that will hope- fully refine the longitudinal picture of this grow- ing population, the prenatally cocaine-exposed infants. The following section will briefly de- scribe cocaine's recent epidemic and its "presen- tation" approximately 15 years ago. Presentation and Prevalence In the mid 1980s, cocaine became a health and social issue as hospitals across the country were recipients of newborns of mothers who used co- caine during pregnancy. Although the extent of the cocaine dependence was not known, the Na- tional Institute on Drug Abuse estimated that, in 1985, 1.96 million women aged 18 years and older used cocaine, representing an alarming 59% increase from 1982.1 Within this group of women, cautious estimates of cocaine-exposed children born each year was 100,000. By the year 2000, it was estimated that more than 500,000 such deliveries would occur, and some predicted that this might climb as high as 4 million. 2 The latitude of these numbers suggested that a major social problem had emerged and that immediate attention was warranted. Because of the rapid appearance of prenatally cocaine-exposed infants, the professional com- munity was unprepared for its dramatic presen- tation. Early, uneducated reports often misrepre- sented the effects of cocaine exposure on infants' medical and developmental status and misguided the scientific communities' attempts to fully understand this problem. In response, a flood of studies have been conducted to more appropriately address the complex issues and to accurately determine the extent to which co- caine exposure impacts children's development. In initial reports, Chasnoff et al, s noted that child-bearing women who intravenously injected or intranasally administered cocaine were at in- creased risk for perinatal complications such as From the Department of Pediatrics, The University of Texas Health Science Center-Houston, TX. Address reprint requests to Susan H. Landry, PhD, Department of Pediatrics, The University of Texas Health Science Center, 6431 Fannin, PV608, Houston, TX 77030. Copyright 9 1996 by W.B. Saunders Company 0146-0005/96/2002-0005505.00/0 Seminars in Perinatology, Vol 20, No 2 (April), 1996: pp 99-106 99