Prenatal drug exposure and maternal and infant feeding behaviour.

OBJECTIVE: To evaluate feeding difficulties and maternal behaviour during a feeding session with 1 month old infants prenatally exposed to cocaine and/or opiates. METHODS: The study is part of the maternal lifestyle study, which recruited 11 811 subjects at four urban hospitals, then followed 1388 from 1 to 36 months of age. Exposure to cocaine and opiates was determined by maternal interview and meconium assay. At the 1 month clinic visit, biological mothers were videotaped while bottle feeding their infants. This sample included 364 exposed to cocaine, 45 exposed to opiates, 31 exposed to both drugs, and 588 matched comparison infants. Mothers were mostly black, high school educated, and on public assistance. Videotapes were coded without knowledge of exposure status for frequency, duration and quality of infant sucking, arousal, feeding problems, and maternal feeding activity and interaction. RESULTS: No cocaine effects were found on infant feeding measures, but cocaine-using mothers were less flexible (6.29 v 6.50), less engaged (5.77 v 6.22), and had shorter feeding sessions (638 v 683 seconds). Opiate exposed infants showed prolonged sucking bursts (29 v 20 seconds), fewer pauses (1.6 v 2.2 per minute), more feeding problems (0.55 v 0.38), and increased arousal (2.59 v 2.39). Their mothers showed increased activity (30 v 22), independent of their infants' feeding problems. CONCLUSIONS: Previous concerns about feeding behaviour in cocaine exposed infants may reflect the quality of the feeding interaction rather than infant feeding problems related to prenatal exposure. However, opiate exposed infants and their mothers both contributed to increased arousal and heightened feeding behaviour.

Interpreting research on prenatal substance exposure in the context of multiple confounding factors.

Fetal exposure to specific drugs often occurs in the context of polydrug use, medical complications, and social/environmental risks. Early reports of severe developmental consequences of fetal exposure to illicit drugs, for example, cocaine, have largely been unsupported by recent studies that take these factors into account. Using a database of published studies on cocaine exposure, this article examines how confounding factors are controlled by recruitment and statistical strategies. Rather than attempting to reduce the impact of these factors, it is suggested that multiple risks in children's lives should be included in models of developmental outcomes along with drug exposure. Understanding the complexity of multiple risks in the child's environment and the subtlety of drug exposure effects can guide the choice of clinical treatment and intervention.

Prenatal cocaine exposure and child development: what do we know and what do we do?

The literature remains unclear about the effects of prenatal cocaine exposure on child development. Meanwhile, the implications for public policy and treatment and for our scientific understanding of the toxicity of cocaine are substantial. In this article we describe; (1) our current understanding of the effects of prenatal cocaine use and child outcome, (2) the issues that need to be investigated, and (3) implications for treatment of cocaine exposed children. Findings from our database of the published literature shows that our knowledge is still limited, scattered, and compromised by methodological problems that mitigate any conclusions about whether or not or how prenatal cocaine exposure affects child outcome. The cocaine problem is more complicated than first envisioned--it is a multifactorial problem including the use of other drugs, parenting, and environmental lifestyle issues. However, we also show that, even though the effects may be more subtle than initially anticipated, prenatal cocaine exposure will substantially increase in the number of school age children who will need special education services. Clinicians working with these children and families need to be prepared to address psychosocial and environmental issues, as well as developmental performance, in order to optimize their assessment and intervention.

Effects of good form and spatial frequency on global precedence.

Does the global precedence effect depend on the goodness of the global form and low spatial frequencies? In Experiments 1 and 2, under a variety of attentional and task conditions, a global advantage in response time (RT) occurred in "good," many-element compound patterns but not in "poor," few-element patterns (unless the local elements were too small to be easily recognized). Symmetric interference effects were found in all patterns, however, suggesting that global and local information were encoded in parallel and that the global advantage in RT involved some postperceptual processes. Experiments 3A and 3B showed that the global advantage in RT and perceived pattern goodness depend on low spatial frequencies: Lowpass-filtered patterns rated as "good" showed the usual global advantage in RT, but highpass-filtered, many-element forms rated as "poor" did not. These findings suggest that a global advantage in RT requires an unambiguous global form conveyed by low spatial frequencies.